Minor Fine-Tuning Scheduler Tutorial Updates for Lightning 1.9.x

[speediedan]

What does this PR do?

Three minor updates to the Fine-Tuning Scheduler tutorial to better support the release of Lightning 1.9.x (supported by Fine-Tuning Scheduler 0.4.x)

• updated the list of supported strategies (Multi-phase Scheduled Fine-Tuning with FSDP is now supported! Noted deprecation of Fairscale-based strategies like ddp_sharded)
  • See the FSDP tutorial here if interested.
• Added references to StrategyAdapters. If users want to extend Fine-Tuning Scheduler (FTS) to use a custom, currently unsupported strategy or override current FTS behavior in the context of a given training strategy, subclassing StrategyAdapter is now a way to do so. See FSDPStrategyAdapter for an example implementation.
• replaced a typehint reference to a datasets class (Batch) that had been replaced in 2.8.0 necessitating the package ceiling in the FTS (0.3.x) (Lightning 1.8.x) version of the tutorial

I recognize #224 might need to get merged before this PR can be. When #224 is passing, I'll update this PR to verify it complies with the new ruff validation/transformation. ruff looks amazing btw!

Before submitting

• Was this discussed/approved via a Github issue? (no need for typos and docs improvements)
• Did you make sure to update the docs?
• Did you write any new necessary tests?

[codecov]

Codecov Report

Merging #225 (ae1616f) into main (cc59322) will not change coverage.
The diff coverage is n/a.

Additional details and impacted files

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