chore(deps): allow installation of guzzlehttp/psr7:3 (#24)

Author: GrahamCampbell

composer.json

@@ -15,7 +15,7 @@
     "require": {
         "php": "^8.2",
         "ext-mbstring": "*",
-        "guzzlehttp/psr7": "^2.0",
+        "guzzlehttp/psr7": "^2.0 | ^3.0",
         "phpunit/phpunit": "^11.5 | ^12 | ^13",
         "symfony/css-selector": ">=4.4.24 <9.0"
     },