Add workflow to run PHP compat testing

.github/workflows/php-compat.yml

@@ -0,0 +1,45 @@
+name: PHP Compatibility
+
+on:
+  push:
+    branches:
+      - develop
+      - trunk
+    paths:
+      - '**.php'
+  pull_request:
+    branches:
+      - develop
+    paths:
+      - '**.php'
+
+jobs:
+  php-compatibility:
+    runs-on: ubuntu-latest
+
+    steps:
+    - uses: actions/checkout@v4
+      with:
+        fetch-depth: 0
+
+    - name: Setup proper PHP version
+      uses: shivammathur/setup-php@v2
+      with:
+        php-version: 7.4
+
+    - name: Get composer cache directory
+      id: composer-cache
+      run: echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
+
+    - name: Cache dependencies
+      uses: actions/cache@v3
+      with:
+        path: ${{ steps.composer-cache.outputs.dir }}
+        key: ${{ runner.os }}-composer-${{ hashFiles('**/composer.lock') }}
+        restore-keys: ${{ runner.os }}-composer-
+
+    - name: Install dependencies
+      run: composer install --prefer-dist
+
+    - name: Run PHP Compatibility
+      run: ./vendor/bin/phpcs --standard=./phpcs-compat.xml -p .

composer.json

@@ -16,7 +16,7 @@
     }
   ],
   "require": {
-    "php": ">=7.2"
+    "php": ">=7.4"
   },
   "require-dev": {
     "10up/phpcs-composer": "dev-master",

phpcs-compat.xml

@@ -0,0 +1,19 @@
+<?xml version="1.0"?>
+<ruleset name="PHPCompatibilityWP">
+	<description>PHP Compatibility checks only</description>
+
+	<!-- Files to check -->
+	<arg name="extensions" value="php"/>
+	<file>.</file>
+
+	<rule ref="PHPCompatibilityWP" />
+
+	<exclude-pattern>*/dist/*</exclude-pattern>
+	<exclude-pattern>*/languages/*</exclude-pattern>
+	<exclude-pattern>*/tests/*</exclude-pattern>
+	<exclude-pattern>*/node_modules/*</exclude-pattern>
+	<exclude-pattern>*/vendor/*</exclude-pattern>
+
+	<config name="minimum_supported_wp_version" value="5.7"/>
+	<config name="testVersion" value="7.4-"/>
+</ruleset>

phpcs.xml

@@ -5,4 +5,12 @@
 	<rule ref="10up-Default" />
 	<exclude-pattern>*/dist/*</exclude-pattern>
 	<exclude-pattern>*/tests/*</exclude-pattern>
+
+	<config name="minimum_supported_wp_version" value="5.7"/>
+	<config name="testVersion" value="7.4-"/>
+
+	<!-- Exclude the PHPCompatibilityWP ruleset -->
+	<rule ref="PHPCompatibilityWP">
+		<exclude name="PHPCompatibilityWP"/>
+	</rule>
 </ruleset>