Remove CLANG_TIDY_ARGS to support run-clang-tidy (backport of #3640) (#3643)

The run-clang-tidy version shipped in current humble-ci Docker images
no longer accepts the `--fix --fix-errors --format-style=file` flags
that CLANG_TIDY_ARGS was passing through, so every humble PR has been
red on the `humble-ci + ikfast + clang-tidy (delta)` check.

Mirror what #3640 did on main (and #3642 backported to jazzy): drop
the env var entirely so run-clang-tidy gets invoked with its defaults.

Co-authored-by: Nathan Brooks <nathanbrooks@picknik.ai>
Co-authored-by: Claude Opus 4.7 <noreply@anthropic.com>

Author: 3 people

.github/workflows/ci.yaml

@@ -31,7 +31,6 @@ jobs:
     env:
       CXXFLAGS: >-
         -Wall -Wextra -Wwrite-strings -Wunreachable-code -Wpointer-arith -Wredundant-decls
-      CLANG_TIDY_ARGS: --fix --fix-errors --format-style=file
       DOCKER_IMAGE: moveit/moveit2:${{ matrix.env.IMAGE }}
       UPSTREAM_WORKSPACE: >
         moveit2.repos