Also remove stuttering from the target names by dropping the 'dawn_' prefix.
Bug: dawn:1275
Change-Id: I3263f1236f71bf23795b4b12670ad3535822a537
Reviewed-on: https://dawn-review.googlesource.com/c/dawn/+/79062
Reviewed-by: Corentin Wallez <cwallez@chromium.org>