json feature always requires base64 feature

[eagletmt]

It should fix build failure when only json feature is enabled.

% cargo build --no-default-features --features json
error[E0433]: failed to resolve: use of undeclared crate or module `base64`
   --> parquet/src/record/api.rs:691:46
    |
691 |             Field::Bytes(b) => Value::String(base64::encode(b.data())),
    |                                              ^^^^^^ use of undeclared crate or module `base64`

For more information about this error, try `rustc --explain E0433`.
error: could not compile `parquet` due to previous error

Which issue does this PR close?

Closes #2667 .

Rationale for this change

base64 is required to compile Field::to_json_value() function.
I considered alternative of replacing #[cfg(any(feature = "json", test)] with #[cfg(any(all(feature = "json", feature = "base64"), test)] , but I noticed that all json features require base64. So I chose to modify parquet/Cargo.toml instead of parquet/src/record/api.rs.

What changes are included in this PR?

I've added base64 to json feature.

Are there any user-facing changes?

No.

[tustvold]

Thank you

[ursabot]

Benchmark runs are scheduled for baseline = a37c038 and contender = 613b66b. 613b66b 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-rs-commits is not supported on ec2-t3-xlarge-us-east-2] ec2-t3-xlarge-us-east-2
[Skipped ⚠️ Benchmarking of arrow-rs-commits is not supported on test-mac-arm] test-mac-arm
[Skipped ⚠️ Benchmarking of arrow-rs-commits is not supported on ursa-i9-9960x] ursa-i9-9960x
[Skipped ⚠️ Benchmarking of arrow-rs-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