ci: cache the Shopware project, drop duplicate install, reuse the tested zip in release

- phpunit: cache the prepared project (vendor + phpunit) monthly via cache restore/save;
  drop system:install/plugin:install (TestBootstrapper installs into its own test DB, so
  every migration ran twice, ~5.5 min each); relax InnoDB durability on the CI database
- package: save the tested zip keyed by the commit's tree hash; release restores it and
  only re-packages on a miss, but always validates and asserts the zip
- cancel superseded PR runs (concurrency)

Co-Authored-By: Claude Sonnet 5.5 <noreply@anthropic.com>

.gitea/workflows/release.yml

@@ -49,8 +49,22 @@ jobs:
             echo "skip=false" >> "$GITHUB_OUTPUT"
           fi
 
-      - uses: actions/cache@v4
+      # Reuse the zip the PR workflow already built and tested for this exact tree.
+      - name: Tree hash of this commit
         if: steps.meta.outputs.skip == 'false'
+        id: tree
+        run: echo "hash=$(git rev-parse "${GITHUB_SHA}^{tree}")" >> "$GITHUB_OUTPUT"
+
+      - name: Restore the tested zip from the PR run
+        if: steps.meta.outputs.skip == 'false'
+        id: prebuilt
+        uses: actions/cache/restore@v4
+        with:
+          path: .build/package.zip
+          key: plugin-zip-${{ steps.tree.outputs.hash }}
+
+      - uses: actions/cache@v4
+        if: steps.meta.outputs.skip == 'false' && steps.prebuilt.outputs.cache-hit != 'true'
         with:
           path: |
             ~/.npm
@@ -58,12 +72,16 @@ jobs:
           key: swcli-${{ runner.os }}-${{ hashFiles('composer.json', 'src/Resources/app/**/package*.json') }}
           restore-keys: swcli-${{ runner.os }}-
 
-      - name: Package extension (prebuilt admin/storefront assets)
-        if: steps.meta.outputs.skip == 'false'
+      - name: Package extension (only if the tested zip is not available)
+        if: steps.meta.outputs.skip == 'false' && steps.prebuilt.outputs.cache-hit != 'true'
         run: |
-          shopware-cli extension package . --output-directory .build \
-            --filename "${{ steps.meta.outputs.zip }}" --git-commit "$GITHUB_SHA"
+          shopware-cli extension package . --output-directory .build             --filename package.zip --git-commit "$GITHUB_SHA"
 
+      - name: Name the zip
+        if: steps.meta.outputs.skip == 'false'
+        run: mv .build/package.zip ".build/${{ steps.meta.outputs.zip }}"
+
+      # Cheap, and guards against a bad cache entry: always validate what ships.
       - name: Validate packaged zip
         if: steps.meta.outputs.skip == 'false'
         run: shopware-cli extension validate ".build/${{ steps.meta.outputs.zip }}"