Make datafusion-sql depend on arrow-schema instead of arrow

[mbrobbel]

Rationale for this change

The datafusion-sql crate only needs types from arrow-schema so this PR reflects that in the dependencies of that crate.

The full arrow crate is still in the dependency tree via the other datafusion dependencies, but this might change later.

What changes are included in this PR?

Make datafusion-sql depend on arrow-schema instead of arrow.

Are these changes tested?

Covered by existing tests.

Are there any user-facing changes?

No.

[alamb]

Looks like a good plan to me -- thank you @mbrobbel

There is a CI check that needs to be fixed (run cargo update for datafusion-cli) but otherwise this is ready to go

[alamb]

Thanks @mbrobbel

[ursabot]

Benchmark runs are scheduled for baseline = 78ac53a and contender = 38e9f30. 38e9f30 is a master commit associated with this PR. Results will be available as each benchmark for each run completes.
Conbench compare runs links:
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on ec2-t3-xlarge-us-east-2] ec2-t3-xlarge-us-east-2
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on test-mac-arm] test-mac-arm
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on ursa-i9-9960x] ursa-i9-9960x
[Skipped ⚠️ Benchmarking of arrow-datafusion-commits is not supported on ursa-thinkcentre-m75q] ursa-thinkcentre-m75q
Buildkite builds:
Supported benchmarks:
ec2-t3-xlarge-us-east-2: Supported benchmark langs: Python, R. Runs only benchmarks with cloud = True
test-mac-arm: Supported benchmark langs: C++, Python, R
ursa-i9-9960x: Supported benchmark langs: Python, R, JavaScript
ursa-thinkcentre-m75q: Supported benchmark langs: C++, Java