serviceconfig: regularly update sdk.yaml with new APIs to drive language onboarding #4856
Description
Improve the overall onboarding experience driven through sdk.yaml e.g. by somehow regularly updating sdk.yaml with new APIs to generate as part of our workflow.
Originally posted by @noahdietz in #4556
sdk.yaml should be the source of truth for what APIs are available to be generated, as well as any necessary, language-agnostic configuration. This means it needs to be regularly updated with new APIs added to googleapis that we could generate clients for.
This should not be reductive in that such a process should not remove entries we've added manually.
This may depend on where sdk.yaml resides (related to #4852), but we likely want to see a librarianops command to assist here.
A back-of-the-napkin heuristic could be to scan googleapis for versioned API paths containing service config YAML files that also have a publishing section (indicating client libraries were requested), and add entries for those paths to sdk.yaml if they do not exist already.