Revert "webnn: implement reverse operator"

This reverts commit 0459ac1a9b94c1dd3e11410f7fb74f0a8e2ddeaf.

Reason for revert: https://ci.chromium.org/ui/p/chromium/builders/ci/mac14-arm64-rel-tests/12103/test-results?sortby=&groupby=

Original change's description:
> webnn: implement reverse operator
>
> This CL adds IDL and mojo definition of reverse operator according to
> the spec issue [1] and implements it on DirectML backend.
>
> [1] webmachinelearning/webnn#773
>
> Bug: 376707210
> Change-Id: I0d42b49b87ce243db9d44512e6000c7ee901077b
> Cq-Include-Trybots: luci.chromium.try:win11-blink-rel, mac14.arm64-blink-rel, mac15.arm64-blink-rel, linux-blink-rel
> Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5979825
> Commit-Queue: ningxin hu <ningxin.hu@intel.com>
> Auto-Submit: Shiyi Zou <shiyi.zou@intel.com>
> Reviewed-by: Austin Sullivan <asully@chromium.org>
> Reviewed-by: ningxin hu <ningxin.hu@intel.com>
> Cr-Commit-Position: refs/heads/main@{#1382078}

Bug: 376707210
Change-Id: Ie7ddada84b0e196d70da5cc42fab2c4ba2b0a13a
Cq-Include-Trybots: luci.chromium.try:win11-blink-rel, mac14.arm64-blink-rel, mac15.arm64-blink-rel, linux-blink-rel
No-Presubmit: true
No-Tree-Checks: true
No-Try: true
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/6013929
Commit-Queue: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Bot-Commit: Rubber Stamper <rubber-stamper@appspot.gserviceaccount.com>
Reviewed-by: Yoichi Osato <yoichio@chromium.org>
Owners-Override: Yoichi Osato <yoichio@chromium.org>
Auto-Submit: Yoichi Osato <yoichio@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1382142}