[clang-tools-extra] [clang-tidy][docs] Fix broken redundant-void-arg documentation. NFC. (PR #212692)

[Zeyi Xu via cfe-commits]

zeyi2 wrote:

Preview looks like this:

<img width="1228" height="566" alt="image" src="https://github.com/user-attachments/assets/95fa4a40-529a-4106-83ec-7ae582ea8ec6" />


https://github.com/llvm/llvm-project/pull/212692