Fix PHPCompatibility dependency conflict

- Remove PHPCompatibility packages from composer.json (conflicts with WPCS 3.x)
- Remove PHPCompatibilityWP rules from phpcs.xml.dist
- Add dedicated phpcompat.yml workflow for PHP 7.4-8.5 compatibility checks
- PHP compatibility now runs in isolated environment with PHPCS 4.x
- Resolves composer dependency conflict between WPCS 3.x (requires PHPCS 3.x) and PHPCompatibility 10.x (requires PHPCS 4.x)

Author: ajaydsouza

.github/workflows/phpcompat.yml

@@ -0,0 +1,54 @@
+name: PHP Compatibility
+
+on:
+  push:
+    paths-ignore:
+      - '**.md'
+      - '**.txt'
+  pull_request:
+    paths-ignore:
+      - '**.md'
+      - '**.txt'
+  workflow_dispatch: {}
+
+jobs:
+  phpcompat:
+    name: 'PHP Compatibility Check'
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Install PHP
+        uses: shivammathur/setup-php@v2
+        with:
+          php-version: '8.0'
+          coverage: none
+
+      # Create isolated environment for PHPCompatibility with PHPCS 4.x
+      - name: Setup PHPCompatibility
+        run: |
+          mkdir phpcompat-tools
+          cd phpcompat-tools
+          composer init --name="temp/phpcompat" --type=project --no-interaction
+          composer config allow-plugins.dealerdirect/phpcodesniffer-composer-installer true
+          composer require --dev \
+            squizlabs/php_codesniffer:"^4.0" \
+            phpcompatibility/php-compatibility:"dev-develop" \
+            dealerdirect/phpcodesniffer-composer-installer:"^1.0" \
+            --no-interaction
+
+      # Check PHP 7.4 through 8.5 compatibility
+      - name: Check PHP Compatibility (7.4-8.5)
+        run: |
+          cd phpcompat-tools
+          ./vendor/bin/phpcs -p \
+            --standard=PHPCompatibility \
+            --runtime-set testVersion 7.4-8.5 \
+            --extensions=php \
+            --ignore=*/vendor/*,*/node_modules/*,*/tests/*,*/phpunit/*,*/freemius/* \
+            ../ || exit_code=$?
+          
+          # Exit with the phpcs exit code (if set)
+          exit ${exit_code:-0}

composer.json

@@ -29,8 +29,6 @@
         "php-stubs/wordpress-stubs": "^6",
         "wp-coding-standards/wpcs": "^3",
         "dealerdirect/phpcodesniffer-composer-installer": "^1",
-        "phpcompatibility/phpcompatibility-wp": "*",
-        "phpcompatibility/php-compatibility": "dev-develop as 9.99.99",
         "yoast/phpunit-polyfills": "^3",
         "phpunit/phpunit": "^9 || ^10 || ^11 || ^12"
     },

phpcs.xml.dist

@@ -37,8 +37,10 @@
 	<rule ref="Generic.Commenting.Todo"/>
 	<rule ref="Generic.WhiteSpace.DisallowSpaceIndent.SpacesUsed"/>
 
-	<!-- Check for PHP 7.4+ compatibility. -->
-	<config name="testVersion" value="7.4-"/>
-	<rule ref="PHPCompatibilityWP"/>
+
+
+	<!-- Note: PHP Compatibility checks are run in a separate GitHub Actions workflow
+	     (.github/workflows/phpcompat.yml) due to dependency conflicts between
+	     WPCS 3.x (requires PHPCS 3.x) and PHPCompatibility 10.x (requires PHPCS 4.x) -->
 
 </ruleset>