Deprecate old docs pages #1154
Description
We want to remove references to the legacy client from the public docs. We should do a review of old docs pages, and make sure we have matching samples for the new data client or autogenerated admin client
This may allow us to drop the patch_devsite_roc.py script, and possibly change devsite renderers (b/345809627)
As part of this, we need to update any region tags in the sample folder that currently use the legacy client, to use the autogenerated clients instead. That should update the public docs to use the new samples
We may also need to re-enable snippetgen for the admin client