ci: fix PHP matrix to 8.2-8.4 and add .phpunit.cache to gitignore

PHPUnit 11 and orchestra/testbench 10 both require PHP 8.2+. Drop PHP 8.1 from the test matrix. Add .phpunit.cache/ and phpunit.xml.bak to .gitignore (artifacts from phpunit.xml migration).

Author: KroderDev

.github/workflows/php.yml

@@ -44,7 +44,7 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        php: ["8.1", "8.2", "8.3", "8.4"]
+        php: ["8.2", "8.3", "8.4"]
 
     steps:
       - uses: actions/checkout@v4

.gitignore

@@ -1,5 +1,7 @@
 composer.phar
 .phpunit.result.*
+.phpunit.cache/
+phpunit.xml.bak
 /vendor/
 
 # Commit your application's lock file https://getcomposer.org/doc/01-basic-usage.md#commit-your-composer-lock-file-to-version-control