Add .h to the list of overrides.

[eugeneo]

This is a lazy fix for #204

In my case it prints a bunch of warnings of "-fsyntax-only" but generates usable compile_commands.json

This is how my version can be tested, add this to MODULE.bazel:

git_override(
    module_name = "hedron_compile_commands",
    remote = "https://github.com/eugeneo/bazel-compile-commands-extractor.git",
    commit = "844279a911d0a0adca480b299799f03f65290cce",
)