chore(firestore): skip pipeline verification tests outside enterprise db

[daniel-sanche]

Fixing problems with system tests (I'm not entirely sure why they started popping up now)

• tests attempt to run pipeline verification tests on all test dbs. Pipelines mode is only supported on enterprise databases, so we should skip the test on unsupported environments
• added unique ids to prevent parallel tests from interfering
• [improvement] use pytest subtests to separate pipeline validation from rest of test

Diff is more complex than it should be, because adding subtests changed indentation

[gemini-code-assist]

Code Review

This pull request updates the verify_pipeline function in both synchronous and asynchronous system tests to include checks for the Firestore emulator and enterprise database requirements. The reviewer recommends using pytest.skip() instead of print() and return to ensure that tests are accurately reported as skipped in the test results, rather than appearing as passed when the conditions are not met.

[chalmerlowe]

LGTM. Needs one minor fix to the documentation string for spelling/grammar.

NOTE: I don't think it is necessary for this PR, but it seems like it would be a useful future refactor to extract out the function(s) to a helper file in the repo rather than duplicating all that code. Especially since each function is so complicated with multiple levels of nesting, and so many conditionals.

That would probably be a good task for Gemini Code Assist and company.

[daniel-sanche]

Thanks for the review. Yeah, unfortunately there's a lot of mostly-duplicated code in this repo currently between the sync/async implementations. I'm hoping to clean it up using crosssync, once we move that outside the bigtable repo