Run tests on PHP 8.4 and update test environment

Builds on top of #172 and ports #181 to v1.

Author: WyriHaximus

.github/workflows/ci.yml

@@ -7,10 +7,11 @@ on:
 jobs:
   PHPUnit:
     name: PHPUnit (PHP ${{ matrix.php }})
-    runs-on: ubuntu-22.04
+    runs-on: ubuntu-24.04
     strategy:
       matrix:
         php:
+          - 8.4
           - 8.3
           - 8.2
           - 8.1
@@ -40,13 +41,13 @@ jobs:
 
   PHPUnit-macOS:
     name: PHPUnit (macOS)
-    runs-on: macos-12
+    runs-on: macos-14
     continue-on-error: true
     steps:
       - uses: actions/checkout@v4
       - uses: shivammathur/setup-php@v2
         with:
-          php-version: 8.2
+          php-version: 8.4
           coverage: xdebug
           ini-file: development
       - run: composer install