webnn: add float32 tests for gru and gruCell operators
This CL is to add some float32 conformance tests for gru and gruCell
operators based from existed gru tests of ONNX CTS.
Bug: 356298361
Change-Id: I24eff51c2e45384311946801831c9bae2e02a36f
Cq-Include-Trybots: luci.chromium.try:win11-blink-rel,mac14-blink-rel,mac14.arm64-blink-rel
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5764428
Auto-Submit: Feng Dai feng.dai@intel.com
Reviewed-by: Austin Sullivan asully@chromium.org
Commit-Queue: Feng Dai feng.dai@intel.com
Reviewed-by: David Baron dbaron@chromium.org
Cr-Commit-Position: refs/heads/main@{#1339988}