Update remat rules

[RissyRan]

Description

To fix #2207:

• Remove checkpoint_dots_with_no_batch_dims with specific rules
• Update minimal_flash rule to minimal_with_context to align current naming
• Test changes accordingly

Tests

Expect compile/unit tests pass.

Checklist

Before submitting this PR, please make sure (put X in square brackets):

• I have performed a self-review of my code.
• I have necessary comments in my code, particularly in hard-to-understand areas.
• I have run end-to-end tests tests and provided workload links above if applicable.
• I have made or will make corresponding changes to the doc if needed.

[gobbleturk]

Thanks Ran!