chore: test wpgraphql-webhooks against WordPress 6.9

- Update "Tested up to" to 6.9 in readme.txt and plugin header
- Fix phpcompatibility/php-compatibility from dev-develop to ^9.3

Author: josephfusco

plugins/wpgraphql-webhooks/composer.json

@@ -18,7 +18,7 @@
 	"require-dev": {
 		"axepress/wp-graphql-cs": "^2.0.0",
 		"axepress/wp-graphql-stubs": "^2.3.0",
-		"phpcompatibility/php-compatibility": "dev-develop as 9.9.9",
+		"phpcompatibility/php-compatibility": "^9.3",
 		"phpstan/extension-installer": "^1.1",
 		"phpstan/phpstan-deprecation-rules": "^2.0.1",
 		"phpstan/phpstan": "^2.0",

plugins/wpgraphql-webhooks/readme.txt

@@ -2,7 +2,7 @@
 Contributors: wpengine
 Tags: GraphQL, Gatsby, Headless, WPGraphQL, React, Rest, Webhooks
 Requires at least: 6.0
-Tested up to: 6.8.1
+Tested up to: 6.9
 Requires PHP: 7.4
 Requires WPGraphQL: 1.8.0
 Stable tag: 0.0.6

plugins/wpgraphql-webhooks/wpgraphql-webhooks.php

@@ -11,7 +11,7 @@
  * Text Domain: graphql-webhooks
  * Domain Path: /languages
  * Requires at least: 6.0
- * Tested up to: 6.8
+ * Tested up to: 6.9
  * Requires PHP: 7.4+
  * Requires Plugins: wp-graphql
  * WPGraphQL requires at least: 1.8.0