feat: Adds timeout for cache download

[tanmay-pnaik]

Fix for https://github.com/subosito/flutter-action/issues/186

Added SEGMENT_DOWNLOAD_TIMEOUT_MINS with parameter set as 2 minutes for download of cache

Link to relevant documentation: https://github.com/actions/cache/blob/main/tips-and-workarounds.md#cache-segment-restore-timeout

[subosito]

Closing this, action/cache v3 already has sensible defaults:

• Reduced segment size to 128MB and segment timeout to 10 minutes to fail fast in case the cache download is stuck.