Fix clippy clippy::vec_init_then_push lint

[gsserge]

Which issue does this PR close?

This is part of #1255

Rationale for this change

It's beneficial to run clippy as strict as possible.

What changes are included in this PR?

This PR enables clippy::vec_init_then_push lint in the arrow crate and fixes all the relates testing code for this check to pass.

Are there any user-facing changes?

No.

[alamb]

Thank you for the contribution @gsserge !

[codecov-commenter]

Codecov Report

Merging #1303 (0eccb4a) into master (8f7c56e) will decrease coverage by 0.00%.
The diff coverage is 100.00%.

@@            Coverage Diff             @@
##           master    #1303      +/-   ##
==========================================
- Coverage   83.01%   83.01%   -0.01%     
==========================================
  Files         180      180              
  Lines       52731    52728       -3     
==========================================
- Hits        43775    43771       -4     
- Misses       8956     8957       +1     

Impacted Files	Coverage Δ
arrow/src/array/array_struct.rs	89.28% <100.00%> (ø)
arrow/src/array/array_union.rs	90.71% <100.00%> (-0.05%)	⬇️
arrow/src/array/builder.rs	86.73% <100.00%> (-0.01%)	⬇️
arrow/src/compute/kernels/limit.rs	100.00% <100.00%> (ø)
parquet_derive/src/parquet_field.rs	65.75% <0.00%> (-0.46%)	⬇️
parquet/src/encodings/encoding.rs	93.71% <0.00%> (+0.19%)	⬆️

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[Dandandan]

Thanks @gsserge !