Before You File a Bug Report Please Confirm You Have Done The Following...

• I have tried restarting my IDE and the issue persists.
• I have updated to the latest version of the packages.
• I have searched for related issues and found none that matched my issue.
• I have read the FAQ and my problem is not listed.

Playground Link

https://typescript-eslint.io/play/#ts=5.5.2&showAST=es&fileType=.tsx&code=CYUwxgNghgTiAEAzArgOzAFwJYHtXwFsoAHYkYAJRA2RlQBUBPMgHnvhAA8MRVgBnePwwwsqAOYA%2BABScAXPHoBKBQG94AbQDS8MYoC6CgMIksGKBCwAvECy2T4AXwBQzlOmx5dqRCBhxgAFkSMkpqWgZmW3YuHj5BYVEJGXlFJXhVZ3h4OBo6QhDyKjzIslklAG5nF2cAN1hvX39yeABeRr8A4NIi8LomMoAicV4-LDBdQWR%2BckGlZyA&eslintrc=N4KABGBEBOCuA2BTAzpAXGUEKQAIBcBPABxQGNoBLY-AWhXkoDt8B6Jge1tiacTJTIAhtEK0ipWsRFCAtonyJoqDJADuIppHBgAviF1A&tsconfig=N4KABGBEDGD2C2AHAlgGwKYCcDyiAuysAdgM6QBcYoEEkJemy0eFYDAruuGAL4g9A&tokens=false

Repro Code

declare function mappedReturnType<T extends string>(x: T): { [K in T]: Capitalize<K> }

function inferredMappedReturnType<T extends string>(x: T) {
  return mappedReturnType(x);
}

var inferred = inferredMappedReturnType("generic is used")

ESLint Config

module.exports = {
  "rules": {
    "@typescript-eslint/no-unnecessary-type-parameters": "warn"
  }
}

tsconfig

{
  "compilerOptions": {
    "strict": true
  }
}

Expected Result

I expected no error

Actual Result

Error on the type parameter in inferredMappedReturnType - "Type parameter T is used only once".

Additional Info

No response