chore(tekton): remove credential sidecar Konflux builds

[squizzi]

Summary

Credential sidecars have been fully replaced by the OpenShell provider model. This PR removes the 8 Tekton pipeline files that were still building unused credential sidecar images (github, google, jira, k8s) in Konflux on every push to main, and updates 5 spec files to reflect the deprecation. Net deletion of ~4,400 lines of unused pipeline YAML.

Ref: ENGPROD-10268

Test plan

• Verify no Konflux pipeline runs trigger for credential sidecar images after merge
• Confirm remaining .tekton/ pipelines still build correctly

[jsell-rh]

🤖 Amber Analysis — PR #469: chore(tekton): remove credential sidecar Konflux builds

Clean, well-scoped cleanup. Removing 8 defunct Tekton pipeline files and updating 5 spec files to reflect the completed migration to the OpenShell provider model.

What I checked:

• 8 Tekton pipeline files — pure deletions (~4,400 lines), no code changes. ENGPROD-10268 referenced. All four credential sidecar images (github, google, jira, k8s) covered.
• 5 spec files — accurate and consistent with the architectural migration. credential-binding.spec.md and identity-boundaries.spec.md correctly mark the sidecar entrypoint as removed; openshell-sandbox-provisioning.spec.md reflects the provider-model as the sole injection mechanism.
• No Go, TypeScript, or production code changes — pure CI pipeline removal + doc updates.

No findings. The changes are well-explained, net-negative (4,400 lines removed), and consistent with the direction established in specs/platform/openshell-sandbox-provisioning.spec.md.

Note: PR is currently in Draft state — flagging in case that wasn't intentional.

Confidence: [95%] High — purely additive deletions with accurate spec documentation.

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— Amber

[JGiola]

For this we can also remove the relevant files in the konflux-release-data repository. We only have to choose if remove everything (and delete all the images in quay) or add the image-controller.appstudio.redhat.com/skip-repository-deletion: "true" annotation to the ImageRepository in an MR, merge that and then create the MR for deleting the resources (this will delete all the konflux resources but will keep the images uploaded to quay).

[squizzi]

image-controller.appstudio.redhat.com/skip-repository-deletion: "true" annotation to the ImageRepository in an MR

I don't think we need to keep these around, I don't really see the value in retaining them, we're going to remove the credential sidecar code eventually it's just out of scope for this specific PR.