Drop PHP 7.3 support

.github/workflows/php.yml

@@ -15,10 +15,6 @@ jobs:
         operating-system: ['ubuntu-latest', 'windows-latest', 'macos-latest']
         php-versions: ['7.4', '8.0', '8.1']
         phpunit-versions: ['latest']
-        include:
-          - operating-system: 'ubuntu-latest'
-            php-versions: '7.3'
-            phpunit-versions: '8.5.21'
 
     steps:
       - name: Setup PHP

composer.json

@@ -33,7 +33,7 @@
         "issues": "https://github.com/ivuorinen/bbcodeparser/issues"
     },
     "require": {
-        "php": ">=7.3 || ^8.0 || ^8.1"
+        "php": ">=7.4 || ^8.0 || ^8.1"
     },
     "require-dev": {
         "dms/phpunit-arraysubset-asserts": "v0.3.1",