Make PHP Version configurable

Author: kieranajp

.github/workflows/test-php.yaml

@@ -1,6 +1,10 @@
 on:
   workflow_call:
     inputs:
+      php_version:
+        required: false
+        type: string
+        default: 8.1
       php_extensions:
         required: false
         type: string
@@ -20,7 +24,7 @@ jobs:
     - name: Setup PHP, with composer and extensions
       uses: shivammathur/setup-php@v2
       with:
-        php-version: 8.1
+        php-version: ${{ inputs.php_version }}
         tools: composer:v2
         extensions: ${{ inputs.php_extensions }}