AC-2841:PHP 7.4 compatibility removal from the codebase

Author: faizan-shk

app/design/adminhtml/Magento/backend/composer.json

@@ -5,7 +5,7 @@
         "sort-packages": true
     },
     "require": {
-        "php": "~7.4.0||~8.1.0",
+        "php": "~8.1.0",
         "magento/framework": "*"
     },
     "type": "magento2-theme",

app/design/frontend/Magento/blank/composer.json

@@ -5,7 +5,7 @@
         "sort-packages": true
     },
     "require": {
-        "php": "~7.4.0||~8.1.0",
+        "php": "~8.1.0",
         "magento/framework": "*"
     },
     "type": "magento2-theme",

app/design/frontend/Magento/luma/composer.json

@@ -5,7 +5,7 @@
         "sort-packages": true
     },
     "require": {
-        "php": "~7.4.0||~8.1.0",
+        "php": "~8.1.0",
         "magento/framework": "*",
         "magento/theme-frontend-blank": "*"
     },