[Misc] Increase default video fetch timeout

[DarkLight1337]

This PR increases the default video fetch timeout to avoid flaky entrypoints tests.

[github-actions]

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[youkaichao]

for record, this can fix tests failure like https://buildkite.com/vllm/fastcheck/builds/8406#01934c8b-b779-4ec1-97c7-9c25fe0f7ba7