[v3-3-test] Stabilize testcontainers provider tests on slow (ARM) CI runners (#68963)

[github-actions]

The mongo provider tests boot a real mongo:8.0 container via testcontainers
in the setup phase of the first test that uses the session fixture. That
bring-up -- image pull, container start, readiness ping -- has to fit inside
the per-test pytest setup-timeout (60s). On the GitHub-hosted ARM canary,
where the image cache is cold and registry/disk throughput is lower, the
pull alone can eat most of that budget, so setup times out and cascades into
"ERROR at setup" across every TestMongoHook test. AMD does not hit this
because it runs on every PR with warm caches; ARM only runs on the cron
canary.

Two complementary changes:

• Pre-pull the testcontainers images (mongo:8.0 + ryuk) on the shared host
  daemon before the timed run, but only in CI and only when the owning
  provider's tests are actually in the selection -- so the slow cold-cache
  pull happens outside the per-test setup timeout. Locally it stays a no-op.

• Give pytest setup/teardown timeouts a higher floor (180s) for container-
  backed fixtures, while keeping execution-timeout at the per-test value so
  genuinely hung tests are still caught quickly.
  (cherry picked from commit 9b0fe28)

Co-authored-by: Jarek Potiuk jarek@potiuk.com