using directory for actions output causes issue like
crbug.com/1315457
ninja explain: output obj/third_party/dawn/src/tint/fuzzers/tint_generate_wgsl_corpus.stamp older than most recent input gen/third_party/dawn/src/tint/fuzzers/fuzzer_corpus_wgsl (1649712735 vs
1649712999)
Use stamp file instead of directory.
Bug: chromium:1315457, chromium:1314527
Change-Id: Ifdf0493e23dbab000513e8f2c0ae4aa8cd76444f
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/86482
Auto-Submit: Fumitoshi Ukai <ukai@google.com>
Reviewed-by: Ryan Harrison <rharrison@chromium.org>
Commit-Queue: Ryan Harrison <rharrison@chromium.org>
Reviewed-by: Ben Clayton <bclayton@google.com>
Commit-Queue: Ben Clayton <bclayton@google.com>