change minimal PHP version to 8.0

Author: efureev

CHANGELOG.md

@@ -4,6 +4,12 @@ All notable changes to this project will be documented in this file.
 
 The format is based on [Keep a Changelog][keepachangelog] and this project adheres to [Semantic Versioning][semver].
 
+## v4.0.0
+
+### Changed
+
+- The package has PHP's minimal version is 8.0 now.
+
 ## v3.1.1
 
 ### Changed

composer.json

@@ -15,8 +15,7 @@
     }
   ],
   "require": {
-    "php": "^7.4|^8.0",
-    "ext-json": "*",
+    "php": "^8.0",
     "ext-mbstring": "*"
   },
   "require-dev": {