Decrease PHPStan version

Author: hxtree

.github/workflows/ci.yml

@@ -65,7 +65,7 @@ jobs:
     strategy:
       matrix:
         php-version:
-          - '8.0'
+          - '7.4'
     steps:
       - uses: actions/checkout@v2
       - uses: php-actions/composer@v6

composer.json

@@ -17,7 +17,7 @@
     "issues": "https://github.com/Ouxsoft/phpmarkup/issues"
   },
   "require": {
-    "php": "^7.3 || ^8.0",
+    "php": ">=7.3",
     "ext-dom": "*",
     "ext-json": "*",
     "ext-libxml": "*",