webnn: Enforce input data type constraints for gather indices
As specified in webmachinelearning/webnn#646
Bug: 328567884
Change-Id: I33eba7e1def430b1cb94e3e7a4868e82c5bbd9a3
Cq-Include-Trybots: luci.chromium.try:mac14-blink-rel,mac14.arm64-blink-rel
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5520313
Reviewed-by: Austin Sullivan asully@chromium.org
Commit-Queue: Lisha Guo lisha.guo@intel.com
Reviewed-by: ningxin hu ningxin.hu@intel.com
Cr-Commit-Position: refs/heads/main@{#1298443}