[Storage] Switch to GCSFuse 2.0

[romilbhardwaj]

GCSFuse 2.0 was recently announced. Most importantly, it adds read caching:

Cloud Storage FUSE V2 provides important stability, functionality, and performance enhancements, including the introduction of a file cache that allows repeat file reads to be served from a local, faster cache storage of choice, such as a Local SSD, Persistent Disk, or even in-memory /tmpfs. The Cloud Storage FUSE file cache makes AI/ML training faster and more cost-effective by reducing the time spent waiting for data, with up to 2.3x faster training time and 3.4x higher throughput observed in training runs. This is especially valuable for multi epoch training and can serve small and random I/O operations significantly faster. The file cache feature is disabled by default and is enabled by passing a directory to 'cache-dir'. See overview of caching for more details.

We should update to v2 and turn on read caching (and set its size as a fixed percentage of available disk?)

[romilbhardwaj]

Closed with #3619.