chore: adds phpstan workflow

Author: JasonTheAdams

.github/workflows/phpstan.yml

@@ -0,0 +1,44 @@
+name: 'PHPStan Static Analysis'
+
+on:
+    push:
+        branches: [ main, develop ]
+    pull_request:
+        branches: [ main, develop ]
+
+jobs:
+    phpstan:
+        name: PHPStan
+        runs-on: ubuntu-latest
+
+        steps:
+            -   name: Checkout code
+                uses: actions/checkout@v4
+                with:
+                    fetch-depth: 1
+
+            -   name: Setup PHP
+                uses: shivammathur/setup-php@v2
+                with:
+                    php-version: '7.2'
+                    coverage: none
+                    tools: composer:v2
+
+            -   name: Get Composer Cache Directory
+                id: composer-cache
+                run: |
+                    echo "dir=$(composer config cache-files-dir)" >> $GITHUB_OUTPUT
+
+            -   name: Cache Composer dependencies
+                uses: actions/cache@v4
+                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 --no-progress --no-suggest --no-interaction
+
+            -   name: Run PHPStan
+                run: composer phpstan