GH-46736: [CI] Disable Parquet in conan-minimum

[kou]

Rationale for this change

#45459 introduced RapidJSON dependency to Parquet support. Conan recipe enables Parquet by default but it doesn't enable RapidJSON by default. So we can't find RapidJSON.

What changes are included in this PR?

Disable Parquet by default.

We should report "Parquet support requires RapidJSON support" to Conan when we release 21.0.0.

Are these changes tested?

Yes.

Are there any user-facing changes?

No.

• GitHub Issue: [CI] conan-minimum build failure with RapidJSON missing error #46736

[kou]

@github-actions crossbow submit -g conan

[github-actions]

Revision: 25cd22b

Submitted crossbow builds: ursacomputing/crossbow @ actions-16c23e405a

Task	Status
conan-maximum
conan-minimum

[hiroyuki-sato]

LGTM👍 Thanks!

[conbench-apache-arrow]

After merging your PR, Conbench analyzed the 4 benchmarking runs that have been run so far on merge-commit 5633582.

There were 66 benchmark results with an error:

• Commit Run on arm64-t4g-2xlarge-linux at 2025-06-09 22:27:44Z
  • tpch (R) with engine=arrow, format=parquet, language=R, memory_map=False, query_id=TPCH-07, scale_factor=1
  • tpch (R) with engine=arrow, format=native, language=R, memory_map=False, query_id=TPCH-01, scale_factor=1
• and 64 more (see the report linked below)

There were no benchmark performance regressions. 🎉

The full Conbench report has more details. It also includes information about 16 possible false positives for unstable benchmarks that are known to sometimes produce them.