api: removes 'wip' from dynamic_modules

[mathetake]

Commit Message: api: removes 'wip' from dynamic_modules
Additional Description:

The dynamic modules API was introduced 6 months ago in #36448 and at the time we didn't have either an implementation or confidence on the configuration API, so it has been marked WIP just in case.

Now that the initial implementation is done, and the documentation as well as the example repository is hosted at envoyproxy/dynamic-modules-examples, early adopters have already tried it out and we haven't heard any concern about the configuration API, so this commit removes the WIP marker towards the next release of Envoy v1.34.

Note that the extension itself is still in alpha, it follows the same caveat like any other alpha extensions.

Risk Level: low
Testing: existing tests.
Docs Changes: Already done in the past commits
Release Notes: Already done in the past commits
Platform Specific Features: n/a

[repokitteh-read-only]

As a reminder, PRs marked as draft will not be automatically assigned reviewers,
or be handled by maintainer-oncall triage.

Please mark your PR as ready when you want it to be reviewed!

🐱

Caused by: #38956 was opened by mathetake.

see: more, trace.

[repokitteh-read-only]

CC @envoyproxy/api-shepherds: Your approval is needed for changes made to (api/envoy/|docs/root/api-docs/).
envoyproxy/api-shepherds assignee is @markdroth
CC @envoyproxy/api-watchers: FYI only for changes made to (api/envoy/|docs/root/api-docs/).

🐱

Caused by: #38956 was opened by mathetake.

see: more, trace.

[mathetake]

oh sorry format

[wbpcode]

LGTM. Thanks for this change. Happy to see dynamic module become more and more mature.