Also remove stuttering from the target names by dropping the 'dawn_' prefix.
Bug: dawn:1275
Change-Id: Iac79f9927010b8e5edeb7e0949092b34431d54dd
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/79061
Reviewed-by: Corentin Wallez <cwallez@chromium.org>