Automatically build deb package on a new version tag (#801)

In #796, I noticed that the deb package was not build since an automation was missing.

With this PR, I add the missing automation.

I tested the workflow in my repo...

    when starting the workflow manually: https://github.com/MrSerth/pgcat/actions/runs/10737879151/job/29780286094
    when drafting a new release: https://github.com/MrSerth/pgcat/actions/runs/10737835796/job/29780146212

Obviously, both workflows failed since I cannot upload to the APT repo. However, the version substitution for the workflow is working correctly (as shown when collapsing the first line of the "Build and release package" step).

.github/workflows/publish-deb-package.yml

@@ -1,6 +1,9 @@
 name: pgcat package (deb)
 
 on:
+  push:
+    tags:
+      - v*
   workflow_dispatch:
     inputs:
       packageVersion:
@@ -16,6 +19,14 @@ jobs:
     runs-on: ${{ matrix.os }}
     steps:
     - uses: actions/checkout@v3
+    - name: Set package version
+      if: github.event_name == 'push'  # For push event
+      run: |
+        TAG=${{ github.ref_name }}
+        echo "packageVersion=${TAG#v}" >> "$GITHUB_ENV"
+    - name: Set package version (manual dispatch)
+      if: github.event_name == 'workflow_dispatch'  # For manual dispatch
+      run: echo "packageVersion=${{ github.event.inputs.packageVersion }}" >> "$GITHUB_ENV"
     - uses: actions-rs/toolchain@v1
       with:
         toolchain: stable
@@ -39,10 +50,10 @@ jobs:
           export ARCH=arm64
         fi
 
-        bash utilities/deb.sh ${{ inputs.packageVersion }}
+        bash utilities/deb.sh ${{ env.packageVersion }}
 
         deb-s3 upload \
           --lock \
           --bucket apt.postgresml.org \
-          pgcat-${{ inputs.packageVersion }}-ubuntu22.04-${ARCH}.deb \
+          pgcat-${{ env.packageVersion }}-ubuntu22.04-${ARCH}.deb \
           --codename $(lsb_release -cs)