style: prefer stack pinning

[TennyZhuang]

I hereby agree to the terms of the RisingWave Labs, Inc. Contributor License Agreement.

What's changed and what's your intention?

Box::pin is unnecessary in such cases.

Checklist For Contributors

• I have written necessary rustdoc comments
• I have added necessary unit tests and integration tests
• I have added fuzzing tests or opened an issue to track them. (Optional, recommended for new SQL features Sqlsmith: Sql feature generation #7934).
• I have demonstrated that backward compatibility is not broken by breaking changes and created issues to track deprecated features to be removed in the future. (Please refer to the issue)
• All checks passed in ./risedev check (or alias, ./risedev c)

Checklist For Reviewers

• I have requested macro/micro-benchmarks as this PR can affect performance substantially, and the results are shown.

Documentation

• My PR DOES NOT contain user-facing changes.

Click here for Documentation

Types of user-facing changes

Please keep the types that apply to your changes, and remove the others.

• Installation and deployment
• Connector (sources & sinks)
• SQL commands, functions, and operators
• RisingWave cluster configuration changes
• Other (please specify in the release note below)

Release note

[codecov]

Codecov Report

Merging #9786 (8820005) into main (0995d35) will decrease coverage by 0.01%.
The diff coverage is 16.66%.

@@            Coverage Diff             @@
##             main    #9786      +/-   ##
==========================================
- Coverage   70.97%   70.97%   -0.01%     
==========================================
  Files        1245     1245              
  Lines      208216   208212       -4     
==========================================
- Hits       147779   147776       -3     
+ Misses      60437    60436       -1     

Flag	Coverage Δ
rust	70.97% <16.66%> (-0.01%)	⬇️

Flags with carried forward coverage won't be shown. Click here to find out more.

Impacted Files	Coverage Δ
...onnector/src/source/filesystem/s3/source/reader.rs	0.00% <ø> (ø)
src/stream/src/executor/backfill.rs	0.00% <ø> (ø)
src/stream/src/executor/lookup/sides.rs	25.00% <ø> (+4.16%)	⬆️
src/stream/src/executor/rearranged_chain.rs	0.00% <0.00%> (ø)
src/stream/src/executor/temporal_join.rs	0.00% <ø> (ø)
src/common/src/util/stream_cancel.rs	98.61% <100.00%> (ø)

... and 6 files with indirect coverage changes

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[BugenZhao]

Is it possible to also replace pin_mut with this macro?

[TennyZhuang]

Is it possible to also replace pin_mut with this macro?

We have to rewrite pin_mut!(f) to let mut f = pin!(f), not sure it's reasonable.