[clang-tools-extra] [clang-tidy] Update google todo checker with style guide changes. (PR #165565)

[via cfe-commits]

github-actions[bot] wrote:

<!--LLVM CODE LINT COMMENT: clang-tidy-->


:warning: C/C++ code linter clang-tidy found issues in your code. :warning:

<details>
<summary>
You can test this locally with the following command:
</summary>

```bash

git diff -U0 origin/main...HEAD -- clang-tools-extra/clang-tidy/google/TodoCommentCheck.cpp |
python3 clang-tools-extra/clang-tidy/tool/clang-tidy-diff.py \
  -path build -p1 -quiet
```

</details>

<details>
<summary>
View the output from clang-tidy here.
</summary>

```
clang-tools-extra/clang-tidy/google/TodoCommentCheck.cpp:31:16: warning: invalid case style for variable 'deprecated_style' [readability-identifier-naming]
   31 |     const bool deprecated_style = !Matches[3].empty();
      |                ^~~~~~~~~~~~~~~~
      |                DeprecatedStyle
   32 |     StringRef Username = deprecated_style ? Matches[5] : Matches[3];
      |                          ~~~~~~~~~~~~~~~~
      |                          DeprecatedStyle
   33 |     StringRef Comment = Matches[6];
   34 | 
   35 |     if (!Username.empty() && (deprecated_style || !Comment.empty()))
      |                               ~~~~~~~~~~~~~~~~
      |                               DeprecatedStyle
```

</details>


https://github.com/llvm/llvm-project/pull/165565