docs: move misplaced upgrade notes to DataFusion 55

[haohuaijin]

Which issue does this PR close?

find this when upgrade datafusion to 55

Rationale for this change

The 54.0.0 upgrade guide lists predicate reordering (#22343) and the new Dialect::Spark variant (#22529), although both changes landed after 54.0.0 and belong to 55.0.0. Users upgrading to 55 should find these changes in that version's guide.

What changes are included in this PR?

• Move both entries from the 54.0.0 guide to the 55.0.0 guide.
• Remove the stale note that 55.0.0 has not been released.

What is the testing strategy for this PR?

Documentation-only change. Verified the feature commits are absent from DataFusion 54.0.0 and present in 55.0.0-rc3, and checked for repository links to the moved headings.

Validation passed:

• git diff --check
• ./ci/scripts/doc_prettier_check.sh --write --allow-dirty
• cargo fmt --all
• cargo clippy --all-targets --all-features -- -D warnings
• All checks in ./dev/rust_lint.sh (resumed individually after updating the local HawkEye installation to the CI version, 7.0.0).

Are there any user-facing changes?

The upgrade notes appear under the correct release. No runtime or API changes.

[codecov-commenter]

Codecov Report

✅ All modified and coverable lines are covered by tests.
✅ Project coverage is 81.97%. Comparing base (6c27203) to head (092fe01).
⚠️ Report is 1 commits behind head on main.

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #25331      +/-   ##
==========================================
- Coverage   81.97%   81.97%   -0.01%     
==========================================
  Files        1137     1137              
  Lines      429889   429889              
  Branches   429889   429889              
==========================================
- Hits       352401   352399       -2     
- Misses      56436    56439       +3     
+ Partials    21052    21051       -1     

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[haohuaijin]

Hi @nuno-faria @comphead , all ci passed in the merge queue, but this pr is removed(not sure why), can you help re-queue this pr.