[blink_apis] Sort `depends_on` list.

`blink_api_proto.py` serializes Blink API metadata using as a textproto.
Some repeated fields may wind up with non-deterministic ordering thereby
causing the resulting API list of to be unstable.

To address this, ideally we should enforce a deterministic ordering on all
repeated fields of the API metadata message. However in practice the
ordering is enforced implicitly for most of the fields other than
`IDLType.depends_on`.

Change-Id: Id2e350c9037dfc8ba238c119ad4133a17b4b79b0
Fixed: 1518420
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/5201589
Reviewed-by: Paul Jensen <pauljensen@chromium.org>
Commit-Queue: Asanka Herath <asanka@chromium.org>
Cr-Commit-Position: refs/heads/main@{#1247964}