Drop support for PHP 8.0 and below

PHP 8.0 is no longer supported. Some of our dependencies now do not work
on PHP 8.0 anymore.

This commit will also run tests on PHP 8.3.

Signed-off-by: Henrique Moody <henriquemoody@gmail.com>

.github/workflows/continuous-integration.yml

@@ -19,9 +19,9 @@ jobs:
     strategy:
       matrix:
         php-version:
-          - "8.0"
           - "8.1"
           - "8.2"
+          - "8.3"
 
     steps:
       - name: Checkout
@@ -62,7 +62,7 @@ jobs:
       - name: Install PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: 8.0
+          php-version: 8.1
           coverage: pcov
           extensions: uopz
           tools: pecl
@@ -96,7 +96,7 @@ jobs:
       - name: Install PHP
         uses: shivammathur/setup-php@v2
         with:
-          php-version: 8.0
+          php-version: 8.3
           coverage: none
 
       - name: Install dependencies

composer.json

@@ -18,7 +18,7 @@
         }
     },
     "require": {
-        "php": "^8.0 || ^8.1 || ^8.2",
+        "php": "^8.1 || ^8.2",
         "respect/stringifier": "^0.2.0",
         "symfony/polyfill-mbstring": "^1.2"
     },

docs/installation.md

@@ -7,4 +7,4 @@ you can install it using [Composer](http://getcomposer.org).
 composer require respect/validation
 ```
 
-Works on PHP 7.3 or above.
+Works on PHP 8.1 or above.