Retry transient artifact download failures (#58841)

Summary:
Pull Request resolved: #58841

GitHub-hosted runners intermittently fail `actions/download-artifact` before
any transfer begins when the artifact service lookup hits a transient DNS
error. The same `Failed to ListArtifacts: ENOTFOUND` signature has affected two
iOS workflows on unrelated `main` commits, while sibling matrix jobs using the
same artifacts completed successfully.

Add a shared composite download action with three bounded attempts and 10-/20-
second backoff, then use it in the two affected workflows. The first two
failures remain visible as warnings, and the final attempt is not allowed to
continue on error, so missing or persistently unavailable artifacts still fail
the caller.

No deterministic introducing commit was identified: the current head only
changes C++ header includes, its Debug sibling passed all five downloads, and
the same DNS signature previously appeared in the SwiftPM new-app workflow.

Changelog: [Internal]

Differential Revision: D123386956

Author: cortinico

.github/actions/download-artifact/action.yml

@@ -0,0 +1,59 @@
+name: Download artifact with retries
+description: Downloads an artifact, retrying transient failures up to two times
+
+inputs:
+  name:
+    description: Artifact name
+    required: true
+  path:
+    description: Destination path
+    required: true
+
+outputs:
+  download-path:
+    description: Absolute path where the artifact was downloaded
+    value: ${{ steps.download-3.outputs.download-path || steps.download-2.outputs.download-path || steps.download-1.outputs.download-path }}
+
+runs:
+  using: composite
+  steps:
+    - name: Download artifact (attempt 1 of 3)
+      id: download-1
+      if: ${{ always() }}
+      continue-on-error: true
+      uses: actions/download-artifact@37930b1c2abaa49bbe596cd826c3c89aef350131 # v7
+      with:
+        name: ${{ inputs.name }}
+        path: ${{ inputs.path }}
+
+    - name: Wait before attempt 2
+      if: ${{ always() && steps.download-1.outcome == 'failure' }}
+      shell: bash
+      run: |
+        echo "::warning::Artifact download failed; retrying in 10 seconds"
+        sleep 10
+
+    - name: Download artifact (attempt 2 of 3)
+      id: download-2
+      if: ${{ always() && steps.download-1.outcome == 'failure' }}
+      continue-on-error: true
+      uses: actions/download-artifact@37930b1c2abaa49bbe596cd826c3c89aef350131 # v7
+      with:
+        name: ${{ inputs.name }}
+        path: ${{ inputs.path }}
+
+    - name: Wait before attempt 3
+      if: ${{ always() && steps.download-2.outcome == 'failure' }}
+      shell: bash
+      run: |
+        echo "::warning::Artifact download failed again; retrying in 20 seconds"
+        sleep 20
+
+    - name: Download artifact (attempt 3 of 3)
+      id: download-3
+      if: ${{ always() && steps.download-2.outcome == 'failure' }}
+      # Deliberately do not continue on error: the last failure must fail the caller.
+      uses: actions/download-artifact@37930b1c2abaa49bbe596cd826c3c89aef350131 # v7
+      with:
+        name: ${{ inputs.name }}
+        path: ${{ inputs.path }}

.github/workflows/e2e-ios-templateapp.yml

@@ -33,22 +33,22 @@ jobs:
         with:
           ruby-version: 2.6.10
       - name: Download React Native Package
-        uses: actions/download-artifact@v7
+        uses: ./.github/actions/download-artifact
         with:
           name: react-native-package
           path: /tmp/react-native-tmp
       - name: Print /tmp folder
         run: ls -lR /tmp/react-native-tmp
       - name: Download ReactNativeDependencies
-        uses: actions/download-artifact@v7
+        uses: ./.github/actions/download-artifact
         with:
           name: ReactNativeDependencies${{ matrix.flavor }}.xcframework.tar.gz
           path: /tmp/third-party
       - name: Print third-party folder
         shell: bash
         run: ls -lR /tmp/third-party
       - name: Download React Native Prebuilds
-        uses: actions/download-artifact@v7
+        uses: ./.github/actions/download-artifact
         with:
           name: ReactCore${{ matrix.flavor }}.xcframework.tar.gz
           path: /tmp/ReactCore
@@ -114,15 +114,15 @@ jobs:
       - name: Run yarn
         uses: ./.github/actions/yarn-install
       - name: Download app
-        uses: actions/download-artifact@v7
+        uses: ./.github/actions/download-artifact
         with:
           name: RNTestProject-${{ matrix.flavor }}
           path: /tmp/RNTestProjectBuild/RNTestProject.app
       - name: Check downloaded folder content
         run: ls -l /tmp/RNTestProjectBuild/RNTestProject.app
       - name: Download React Native Package
         if: ${{ matrix.flavor == 'Debug' }}
-        uses: actions/download-artifact@v7
+        uses: ./.github/actions/download-artifact
         with:
           name: react-native-package
           path: /tmp/react-native-tmp

.github/workflows/test-ios-spm-newapp.yml

@@ -40,27 +40,27 @@ jobs:
       # release/ artifact slots together (and `--download skip` refuses an
       # incomplete slot). Please don't "optimise" this down to one flavor.
       - name: Download ReactCore (Debug)
-        uses: actions/download-artifact@v7
+        uses: ./.github/actions/download-artifact
         with:
           name: ReactCoreDebug.xcframework.tar.gz
           path: /tmp/rc-debug
       - name: Download ReactCore (Release)
-        uses: actions/download-artifact@v7
+        uses: ./.github/actions/download-artifact
         with:
           name: ReactCoreRelease.xcframework.tar.gz
           path: /tmp/rc-release
       - name: Download ReactNativeDependencies (Debug)
-        uses: actions/download-artifact@v7
+        uses: ./.github/actions/download-artifact
         with:
           name: ReactNativeDependenciesDebug.xcframework.tar.gz
           path: /tmp/deps-debug
       - name: Download ReactNativeDependencies (Release)
-        uses: actions/download-artifact@v7
+        uses: ./.github/actions/download-artifact
         with:
           name: ReactNativeDependenciesRelease.xcframework.tar.gz
           path: /tmp/deps-release
       - name: Download React Native package
-        uses: actions/download-artifact@v7
+        uses: ./.github/actions/download-artifact
         with:
           name: react-native-package
           path: /tmp/react-native-tmp