Add scheduled runs to test compatibility with upcoming PHP versions

Author: mpdude

.github/workflows/tests.yml

@@ -5,6 +5,8 @@ on:
         branches:
             - master
     pull_request:
+    schedule:
+        - cron: '10 6 * * 1'
 
 jobs:
     build:
@@ -20,7 +22,7 @@ jobs:
         name: PHP ${{ matrix.php-version }} - ${{ matrix.dependency-version }}
 
         steps:
-            -   uses: actions/checkout@v3
+            -   uses: actions/checkout@v4
             -   name: Install PHP
                 uses: shivammathur/setup-php@v2
                 with: