cirquit/v08 regressions

[cirquit]

What does this PR do? Please describe:
A summary of the change or the issue that is fixed.

• Fixes test regression on main in test_get_shard_dims_work
• Fixes black CVE by upleveling to 26.3.1
• Fixes datetime.utcnow() deprecation
• Adds a few shims back for backwards compatibility from Revise ModelCheckpointLoader #1475, Rename resolve_optional to maybe_resolve #1462, Move trainer, evaluator, and generator to root #1417
• Updated pandas to ~=2.2 for Python 3.12 compatibility when installing .[arrow]
• FlashAttention3 changed its import paths (we did not notice it because we don't require it), needed alignment 4d182fd

[cbalioglu]

LGTM!