refactor: eliminate common-cache, use actions/cache directly

Replace common-cache wrapper with native actions/cache in npm-publish
and php-composer, completing the caching optimization campaign.

Changes:
1. npm-publish (lines 107-114):
   - Replace common-cache with actions/cache@v4.3.0
   - Use hashFiles() for node_modules cache key
   - Support multiple lock files (package-lock, yarn.lock, pnpm, bun)

2. php-composer (lines 177-190):
   - Replace common-cache with actions/cache@v4.3.0
   - Use multiline YAML for cleaner path configuration
   - Use hashFiles() for composer cache key
   - Support optional cache-directories input

Benefits:
- Native GitHub Actions functionality (no wrapper overhead)
- Better performance (no extra action call)
- Simpler maintenance (one less internal action)
- Standard approach used by official actions
- Built-in hashFiles() more efficient than manual sha256sum

Result:
- Eliminates all common-cache usage (reduced from 4 to 0 actions)
- common-cache action can now be deprecated/removed
- Completes caching optimization: 11 → 0 common-cache dependencies

Campaign summary:
- Phase 1: Inline language-version-detect
- Phase 2: Migrate 6 actions to setup-* native caching
- Phase 3: Replace go-lint common-cache with actions/cache
- Phase 4: Eliminate remaining common-cache (npm, php)

php-composer/action.yml

@@ -176,13 +176,15 @@ runs:
 
     - name: Cache Composer packages
       id: composer-cache
-      uses: ivuorinen/actions/common-cache@0fa9a68f07a1260b321f814202658a6089a43d42
+      uses: actions/cache@0057852bfaa89a56745cba8c7296529d2fc39830 # v4.3.0
       with:
-        type: 'composer'
-        paths: vendor,~/.composer/cache${{ inputs.cache-directories != "" && format(",{0}", inputs.cache-directories) || "" }}
-        key-prefix: 'php-${{ inputs.php }}-composer-${{ inputs.composer-version }}'
-        key-files: 'composer.lock,composer.json'
+        path: |
+          vendor
+          ~/.composer/cache
+          ${{ inputs.cache-directories }}
+        key: ${{ runner.os }}-php-${{ inputs.php }}-composer-${{ inputs.composer-version }}-composer-${{ hashFiles('composer.lock', 'composer.json') }}
         restore-keys: |
+          ${{ runner.os }}-php-${{ inputs.php }}-composer-${{ inputs.composer-version }}-composer-
           ${{ runner.os }}-php-${{ inputs.php }}-composer-${{ inputs.composer-version }}-
           ${{ runner.os }}-php-${{ inputs.php }}-composer-
           ${{ runner.os }}-php-${{ inputs.php }}-