blastdns: Fail if the checkout is not the requested version

A version missing from the ref map would check out the default branch and
build the wrong sources under that version number; compare the checkout's
pyproject.toml version with the requested one.

Author: luhenry

.github/workflows/build-blastdns.yml

@@ -109,6 +109,9 @@ jobs:
           ref: ${{ fromJSON(env.BLASTDNS_REFS)[env.BLASTDNS_VERSION] }}
           persist-credentials: false
 
+      - name: Check the checkout is the requested version
+        run: grep -qx "version = \"${BLASTDNS_VERSION}\"" pyproject.toml
+
       - name: Checkout python-wheels
         uses: actions/checkout@3d3c42e5aac5ba805825da76410c181273ba90b1  # v7.0.1
         with: