Box FlightErrror::tonic to reduce size (fixes nightly clippy)

[XiangpengHao]

Which issue does this PR close?

Closes #.

Rationale for this change

When working on the nightly rust, I noticed that clippy warns about FlightError too large, more than 176 bytes.

I think it makes sense to keep the error small (32 bytes), as the Result<...> is used in a lot of places.

This PR basically makes Tonic(tonic::Status) into Tonic(Box<tonic::Status>), which reduces the FlightError from 176 bytes down to 32 bytes.

This adds an extra allocation on error, but should probably be fine as it's not on hot path.

What changes are included in this PR?

Are there any user-facing changes?

[crepererum]

which reduces the FlightError from 176 bytes down to 32 bytes.

can you add a test that checks that, e.g.

#[test]
fn test_error_size() {
    assert_eq!(std::mem::size_of::<FlightError>(), 32);
}

[alamb]

can you add a test that checks that, e.g.

I took the liberty of adding this in 94da215 and pushed to this branch

[alamb]

Thank you @XiangpengHao @crepererum and @lewiszlw

[tustvold]

I think this has been merged by mistake? Is main open for breaking changes yet?

[crepererum]

I think this has been merged by mistake? Is main open for breaking changes yet?

I forgot that, TBH I find it tiring to manually check the release schedule every time.

Edit: filed #7268 to prevent future annoyance.

[alamb]

Update:

• This change was reverted in Revert "Box FlightErrror::tonic to reduce size  #7266
• I have re-created the change in a new PR here: Reapply Box FlightErrror::tonic to reduce size (fixes nightly clippy) #7277