[next.js] - Hello !
I don't think you need both .eslintrc.json and .eslinrc.js.
In fact it might be the root cause of your issue.
The second file seems to override the first.
If you get rid of .eslintrc.json to only keep .eslinrc.js and add the next plugin at the end like :
"env": {
"browser": true,
"es2021": true
},
"extends": [
"eslint:recommended",
"plugin:react/recommended",
"next/core-web-vitals"
],
...
it should fix your problem.