[Test] Fix Release Failures

[lloyd-brown]

This PR fixes two issues with smoke test blocking release:

• The first is with test_launch_fast_with_autostop which is failing due to a new python warning message in the output not expected by the test, we've added an env variable to suppress these warnings in the future.
• The second is with test_managed_jobs_storage, it currently times out because provisioning a spot instance on GCP takes too long, I've increased the timeout.

Both smoke test pass now https://buildkite.com/skypilot-1/smoke-tests/builds?branch=lloyd%2Ffix-release-build.

Tested (run the relevant ones):

• Code formatting: install pre-commit (auto-check on commit) or bash format.sh
• Any manual or new tests for this PR (please specify below)
• All smoke tests: /smoke-test (CI) or pytest tests/test_smoke.py (local)
• Relevant individual tests: /smoke-test -k test_name (CI) or pytest tests/test_smoke.py::test_name (local)
• Backward compatibility: /quicktest-core (CI) or pytest tests/smoke_tests/test_backward_compat.py (local)

[lloyd-brown]

/smoke-test -k test_managed_jobs_storage --gcp

[lloyd-brown]

/smoke-test -k test_launch_fast_with_autostop --gcp

[lloyd-brown]

/smoke-test -k test_launch_fast_with_autostop --gcp

[lloyd-brown]

/smoke-test -k test_launch_fast_with_autostop --gcp

[SeungjinYang]

Thanks @lloyd-brown!

[lloyd-brown]

/smoke-test -k test_endpoint_output_basic