Drop PHP 8.1 and Upgrade PHPUnit to 11.x

Signed-off-by: George Steel <george@net-glue.co.uk>

Author: gsteel

composer.json

@@ -21,7 +21,7 @@
     "config": {
         "sort-packages": true,
         "platform": {
-            "php": "8.1.99"
+            "php": "8.2.99"
         },
         "allow-plugins": {
             "dealerdirect/phpcodesniffer-composer-installer": true
@@ -30,8 +30,8 @@
     "extra": {
     },
     "require": {
-        "php": "~8.1.0 || ~8.2.0 || ~8.3.0 || ~8.4.0 || ~8.5.0",
-        "phpunit/phpunit": "^10.3 || ^11",
+        "php": "~8.2.0 || ~8.3.0 || ~8.4.0 || ~8.5.0",
+        "phpunit/phpunit": "^11.5",
         "psr/container": "^1.0 || ^2.0.2"
     },
     "require-dev": {