refactor(hash-aggr): Disable the legacy aggregation implementation.

[2010YOUY01]

Which issue does this PR close?

Part of #22710
Depends on #24262

Only the last commit belongs to this PR. I’ll rebase onto main after the dependent PR is merged.

Rationale for this change

This PR intends to be the last PR for functionally complete #22710, it logically disable the legacy implementation and fully move to the new refactor.

The legacy implementation is not deleted yet, so if anything goes wrong, we can use the config to revert to the old implementation

set datafusion.execution.enable_migration_aggregate = false;

What changes are included in this PR?

Are these changes tested?

Are there any user-facing changes?

[codecov-commenter]

Codecov Report

❌ Patch coverage is 85.21971% with 111 lines in your changes missing coverage. Please review.
✅ Project coverage is 80.99%. Comparing base (634f0b3) to head (942a35e).
⚠️ Report is 42 commits behind head on main.

Files with missing lines	Patch %	Lines
...sical-plan/src/aggregates/ordered_single_stream.rs	86.74%	49 Missing and 10 partials ⚠️
datafusion/physical-plan/src/aggregates/mod.rs	84.97%	11 Missing and 15 partials ⚠️
...sical-plan/src/aggregates/partial_reduce_stream.rs	57.14%	13 Missing and 2 partials ⚠️
...plan/src/aggregates/aggregate_hash_table/common.rs	88.37%	0 Missing and 5 partials ⚠️
.../aggregates/aggregate_hash_table/common_ordered.rs	60.00%	0 Missing and 2 partials ⚠️
...gates/aggregate_hash_table/ordered_single_table.rs	94.44%	0 Missing and 2 partials ⚠️
...c/aggregates/aggregate_hash_table/partial_table.rs	0.00%	0 Missing and 1 partial ⚠️
...rc/aggregates/aggregate_hash_table/single_table.rs	0.00%	0 Missing and 1 partial ⚠️

Additional details and impacted files

@@            Coverage Diff             @@
##             main   #24263      +/-   ##
==========================================
- Coverage   81.06%   80.99%   -0.07%     
==========================================
  Files        1107     1108       +1     
  Lines      382191   384708    +2517     
  Branches   382191   384708    +2517     
==========================================
+ Hits       309805   311612    +1807     
- Misses      54083    54725     +642     
- Partials    18303    18371      +68     

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