CI: clang-format-check - run only if changes in c/cpp/header files

[pesekon2]

No description provided.

[echoix]

Since it is a required check, we should always have it run.
It is (one of) the fastest of the checks that we have. 30-35 seconds.
clang-format can also format js, json, java and more:
https://clang.llvm.org/docs/ClangFormat.html#standalone-tool

  --assume-filename=<string>     - Set filename used to determine the language and to find
                                   .clang-format file.
                                   Only used when reading from stdin.
                                   If this is not passed, the .clang-format file is searched
                                   relative to the current working directory when reading stdin.
                                   Unrecognized filenames are treated as C++.
                                   supported:
                                     CSharp: .cs
                                     Java: .java
                                     JavaScript: .js .mjs .cjs .ts
                                     Json: .json .ipynb
                                     Objective-C: .m .mm
                                     Proto: .proto .protodevel
                                     TableGen: .td
                                     TextProto: .txtpb .textpb .pb.txt .textproto .asciipb
                                     Verilog: .sv .svh .v .vh

[pesekon2]

Since it is a required check, we should always have it run.

Are you sure? What is the purpose of running it if no change in the PR could cause any change in its result?

It is (one of) the fastest of the checks that we have. 30-35 seconds.

This is true but in our case (many many many checks), it is good to get rid of anything that is not needed. Also, we can burn fewer trees by saving some runs. I plan to move to some of the more demanding ones now but I wanted to start with the quick fixes.

clang-format can also format js, json, java and more: https://clang.llvm.org/docs/ClangFormat.html#standalone-tool

Hmm, any idea then why Java is not mentioned among the supported extensions in the docs of the tool we use: https://github.com/DoozyX/clang-format-lint-action?tab=readme-ov-file#extensions?