Drop EOLed PHP 7.3

Author: simPod

.github/workflows/ci.yaml

@@ -16,7 +16,6 @@ jobs:
     strategy:
       matrix:
         php-version:
-          - "7.3"
           - "7.4"
           - "8.0"
           - "8.1"

composer.json

@@ -9,7 +9,7 @@
         }
     ],
     "require": {
-        "php": "^7.3 || ~8.0.0 || ~8.1.0",
+        "php": "^7.4 || ~8.0.0 || ~8.1.0",
         "ext-json": "*"
     },
     "require-dev": {