typescript version 7 complains about unused generic type even though version 6 does not

### 🔎 Search Terms

"TS6196", "is declared but never used", "unused generic", "noUnusedParameters"

### 🕗 Version & Regression Information

- This changed between versions 6.0.3 and 7.0.2

### ⏯ Playground Link

https://www.typescriptlang.org/play/?#code/C4TwDgpgBAShBmAeAKgPigXigbwFAEgA3AQwBsBXCALimQBpcBfXXecgOwGNgBLAe3ZROAJwjFgEOEnoBVKBAAeE9gBMAzlEJ8eK1AAoSFapu0qAlDSkpUAblYdu-QSLESraA2Uo1kF2Ams7Ni5eASFRcUkAj0NvWj93dDx8UWByYUFkoi8IBnxGO2ZcTgE1YChReABGTHDXKPg9MzsS9jU+UggAOlI+AHM9Sqrm4tLyyoAmWpdIq3ZyAFsAIwhhOhMdfRHW9s6e-sGECe2xioQAZmmItwD55dX9KvOTto7u3oHK57sgA

### 💻 Code

```ts
type Ref = {
value: T,
}

function createRef(value: void): Ref;
function createRef(value: T): Ref;
function createRef(value: T): Ref {
return {
value,
};
}

const ref1 = createRef();
console.log(ref1);
const ref2 = createRef();
console.log(ref2);
const ref3 = createRef(13);
console.log(ref3);
```

### 🙁 Actual behavior

The typescript compiler version 7 fails with following error message:

```
code.ts:5:22 - error TS6196: 'U' is declared but never used.

5 function createRef(value: void): Ref;
~~~~~~~~~~~~~~

Found 1 error in code.ts:5
```

The typescript compiler version 6 succeeds without any errors.

### 🙂 Expected behavior

The typescript compiler version 7 should behave exactly like version 6 i.e. not fail.

### Additional information about the issue

This error only occurs with `noUnusedParameters` set to `true`.

Reproduce the error from the linked Playground using noUnusedParameters and the shown createRef overloads, then trace the compiler’s handling of unused generic type parameters in overload declarations. Add a regression test covering the version-7 behavior and verify that the example no longer reports TS6196 while other unused-parameter diagnostics remain correct.

Written by the indexing model from the issue text.