Begin the deprecation process for the extended and extended_withdeploy builds

[jmooring]

In v0.153.0 we deprecated the libsass transpiler option and removed libwebp. Somewhere around v0.166.0 Hugo will start throwing an error if the transpiler option is set to libsass. At that point we no longer need the extended builds.

Prerequisite

• This needs to happen first: Consider building "withdeploy" release assets #14687

Suggested warning messages

If the user is running the extended edition:

the extended edition is deprecated; please switch to the standard edition

If the user is running the extended/deploy edition:

the extended/deploy edition is deprecated; please switch to the deploy edition