fix: upgrade the generator to protobuf 31 and bazel 7.7.1, and update templates to fix system test

[sofisl]

There were ongoing issues with running the generator, with an old version of protobuf and the c++ errors:

• https://g3doc.corp.google.com/java/com/google/ads/shopping/contentapi/g3doc/platform/client-libraries.md#linker-error-relocation-refers-to-a-discarded-section
• https://critique.corp.google.com/cl/881595129
  updated the generator to match the version of bazel it's on in google3

Also! turns out we weren't running tests! In order to run (and pass) tests, I had to:

• fixed indentation to run tests
• got rid of the bazel compiler flags in-flight
• had to make sure eslint points to the root file so that the generator eslint configurations don't point all the way up to the top-level config. FWIW I don't think we should make this is a single file at the root level of the library but if we did, we'd need to remove the "root" I added to the template
• got rid of the continuous branch for this test since it's a gh action that runs when a pr is opened, so continuous doesn't make sense
• fixed two templates issues which is what we're seeing today that's blocking our tests: 1) an issue with sinon timers that needs sinon to be pinned, 2) the template issue in which evaluates a cjs file as ts.