Do not count deprecation on native-to-js conversion in dicts

There's no point in reporintg deprecated feature use when converting
a native dictionary to JS, since it does not indicate that the page
is actually using the property, only that we're providing it. It would
have made sense if we were to provide an accessor in this case, but this
is not how it is implemented, and we don't have actual usage of
[DeprecateAs] in dicts being returned, so just remote it altogether.

Change-Id: I7efbb24ffe6c6f783c74a73325456189c88c65fa
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5218413
Reviewed-by: Nate Chapin <japhet@chromium.org>
Commit-Queue: Nate Chapin <japhet@chromium.org>
Auto-Submit: Andrey Kosyakov <caseq@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1249692}