add GitHub OAuth token, use --no-check-lock; remove gitea VCS entry

.github/workflows/php.yml

@@ -18,7 +18,7 @@ jobs:
     - uses: actions/checkout@v4
 
     - name: Validate composer.json and composer.lock
-      run: composer validate --strict
+      run: composer validate --strict --no-check-lock
 
     - name: Cache Composer packages
       id: composer-cache
@@ -29,6 +29,10 @@ jobs:
         restore-keys: |
           ${{ runner.os }}-php-
 
+    - name: Configure GitHub OAuth for Composer
+      if: ${{ secrets.GH_COMPOSER_TOKEN != '' }}
+      run: composer config --global github-oauth.github.com ${{ secrets.GH_COMPOSER_TOKEN }}
+
     - name: Install dependencies
       run: composer install --prefer-dist --no-progress