ci(gitea): run CI in a prebuilt PHP image instead of setup-php bootstrap

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AqpXh3hQMMaC74pTjFq4it

.gitea/actions/ci-phpunit/action.yml

@@ -21,7 +21,20 @@ runs:
       shell: bash
       run: command -v svn >/dev/null || (sudo apt-get update -qq && sudo apt-get install -y --no-install-recommends subversion)
 
-    - name: Setup PHP ${{ inputs.php }}
+    - name: Use preinstalled PHP ${{ inputs.php }} (peptide-php image)
+      id: pre
+      shell: bash
+      env:
+        V: ${{ inputs.php }}
+      run: |
+        if command -v "php$V" >/dev/null 2>&1 && command -v composer >/dev/null 2>&1; then
+          update-alternatives --set php "/usr/bin/php$V" >/dev/null 2>&1 || ln -sf "/usr/bin/php$V" /usr/local/bin/php
+          php -v | head -1; echo "hit=true" >> "$GITHUB_OUTPUT"
+        else
+          echo "hit=false" >> "$GITHUB_OUTPUT"
+        fi
+    - name: Setup PHP ${{ inputs.php }} (fallback when not preinstalled)
+      if: ${{ steps.pre.outputs.hit != 'true' }}
       uses: shivammathur/setup-php@v2
       with:
         php-version: ${{ inputs.php }}