feat: drop support for PHP 8.0 and 8.1 (#104)

- Update minimum PHP version requirement from ^8.0 to ^8.2 in
composer.json
- Remove symfony/polyfill-php80 dependency (no longer needed with PHP
8.2+)
- Update README.md to reflect PHP 8.2+ requirement

Co-authored-by: Claude <noreply@anthropic.com>

Author: deviantintegral

README.md

@@ -4,7 +4,7 @@
 
 ## Requirements
 
-* PHP 8.0+
+* PHP 8.2+
 * The `ext-json` extension.
 
 ## Installation

composer.json

@@ -12,15 +12,14 @@
         }
     ],
     "require": {
-        "php": "^8.0",
+        "php": "^8.2",
         "ext-json": "*",
         "jms/serializer": "^3.0",
         "doctrine/annotations": "^2.0",
         "guzzlehttp/psr7": "^2.0",
         "deviantintegral/jms-serializer-uri-handler": "^1.1",
         "deviantintegral/null-date-time": "^1.0",
-        "symfony/console": "^5.0||^6.0",
-        "symfony/polyfill-php80": "^1.20"
+        "symfony/console": "^5.0||^6.0"
     },
     "require-dev": {
         "friendsofphp/php-cs-fixer": "3.92.0",