webnn: Remove support for passing MLActivations for op fusion
Remove the ability to specify op fusions from the web platform layer.
Ops can still be fused, but this is now the responsibility of the
respective WebNN backend
Corresponds to the spec PR merged here:
webmachinelearning/webnn#664
Bug: 341518634
Cq-Include-Trybots: luci.chromium.try:win11-blink-rel,mac14.arm64-blink-rel,mac14-blink-rel
Change-Id: I8a4f2ab708e34087eeb10421596243b17bc8d7e2
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5494397
Reviewed-by: ningxin hu ningxin.hu@intel.com
Reviewed-by: Alex Gough ajgo@chromium.org
Commit-Queue: Austin Sullivan asully@chromium.org
Cr-Commit-Position: refs/heads/main@{#1310724}