Release DataFusion-Python 54.0.0

[timsaucer]

Context

Tracking issue for 54.0.0 release. PR #1532 pre-revved deps to upstream main (rev 3d06bedc), bumped version to 54.0.0, fixed breakage, and landed trivial check-upstream wins. Non-trivial audit follow-ups live in df-54-followups.md and do not block this release.

Once upstream datafusion 54.0.0 ships on crates.io, redo the full sync + release sequence — the GA tag may differ from the pinned main commit.

References

• PR Update datafusion dependency to latest in preparation for DF54 #1532 — pre-rev + compile fixes + trivial audit wins.

df-54-followups.md