update envoy defs to allow `UNWATCH` by mgravell · Pull Request #2824 · StackExchange/StackExchange.Redis

Fix #2823 in combination with envoyproxy/envoy#37620

Note that in passing it occurs that this is an exclusion list, and these exclusions have not been kept up-to-date with new command additions; consequently, the exclusion lists may be incomplete in a few cases. This isn't a huge problem - the command will still fail, but it will fail at the proxy or server instead of at the client.