don't run clang-tidy on third_party

This doesn't usually come up because third_party/ is mostly
only C code and clang-tidy only runs on C++ code, but it's
starting to matter as we roll in Dawn.

Change-Id: I52c64cd55281989dad837d6573c38e8b380861a3
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/280329
Commit-Queue: Mike Klein <mtklein@google.com>
Commit-Queue: Brian Salomon <bsalomon@google.com>
Auto-Submit: Mike Klein <mtklein@google.com>
Reviewed-by: Brian Salomon <bsalomon@google.com>
1 file changed