Fix tests for PHP 7.3+ and add experimental test for PHP 8.1

Author: gmazzap

.github/workflows/php-qa.yml

@@ -19,6 +19,10 @@ jobs:
                     prefer: "highest"
                     ignore-platform: "--ignore-platform-reqs"
                     experimental: true
+                  - php: "8.1"
+                      prefer: "highest"
+                      ignore-platform: "--ignore-platform-reqs"
+                      experimental: true
 
         continue-on-error: ${{ matrix.experimental }}
 
@@ -42,12 +46,11 @@ jobs:
                 dependency-versions: ${{ matrix.prefer }}
                 composer-options: ${{ matrix.ignore-platform }}
 
-            - name: Run unit tests (PHPUnit 9)
+            - name: Migrate PHPUnit config for PHPUnit 9
               if: ${{ (matrix.php >= 7.3) && (matrix.prefer == 'highest') }}
               run: ./vendor/bin/phpunit --migrate-configuration
 
-            - name: Run unit tests (PHPUnit 7)
-              if: ${{ (matrix.php < 7.3) || ((matrix.php == 7.3) && (matrix.prefer == 'lowest')) }}
+            - name: Run unit tests
               run: ./vendor/bin/phpunit
 
     Static_Analisys: