google_api_client_requirements without a #[LegacyRequirementsHook] attribute is deprecated

Problem/Motivation

I have a custom module that depends on this module, and when I run the functional tests for my module I get this warning:

google_api_client_requirements without a #[LegacyRequirementsHook] attribute is deprecated in drupal:11.3.0 and removed in drupal:13.0.0. See https://www.drupal.org/node/3549685

Steps to reproduce

Test a module the depends on this one.

Proposed resolution

I was going to create an MR, but https://www.drupal.org/node/3492429 is problematic. It suggests creating a class (like GoogleAPIClientRequirements) in the Install\Requirements namespace that would return what google_api_client_requirements is returning.

The problem is because that page says "The code must not use any other code from the module as it loaded prior to the module being installed", and that's exactly what google_api_client_requirements does: it calls the google_api_client_load_library function in the module file.

So, one alternative is to just copy and paste google_api_client_load_library as a method in the new GoogleAPIClientRequirements class. That duplication wouldn't be great. Another alternative would be to put that function in a new class and load it from all places where it's used. However, since the module might not be enabled that means GoogleAPIClientRequirements would need to load the new class using require_once instead of it being autoloaded.

Remaining tasks

Figure out how to handle this in a maintainable and preferably elegant way. Or, just have duplicate code and include a note in both places. If the code of google_api_client_load_library needs to change, then it can just be copied and pasted.