Previously, the clang-tidy.yaml workflow would cancel the clang-tidy job
when a comment wasn't prefixed with "/clang-tidy", instead of skipping it.
This cancellation triggered unnecessary email notifications for developers
with GitHub action notifications enabled.
This change modifies the workflow to only run clang-tidy when the
read-toolchain job succeeds, reducing notification noise by properly
skipping the job rather than cancelling it.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#23084