Allow ESLint v9 as peer dependency

Author: FloEdelmann

.github/workflows/CI.yml

@@ -28,12 +28,8 @@ jobs:
       matrix:
         node: [18, 20]
         os: [ubuntu-latest]
-        eslint: [8]
+        eslint: [8, 9]
         include:
-          # On next ESLint version
-          - eslint: ^9.0.0-0
-            node: 20
-            os: ubuntu-latest
           # On old Node version
           - eslint: 8
             node: 17

package.json

@@ -52,7 +52,7 @@
     "node": "^14.17.0 || >=16.0.0"
   },
   "peerDependencies": {
-    "eslint": "^6.2.0 || ^7.0.0 || ^8.0.0"
+    "eslint": "^6.2.0 || ^7.0.0 || ^8.0.0 || ^9.0.0"
   },
   "dependencies": {
     "@eslint-community/eslint-utils": "^4.4.0",