reduce allocation in Record array construction

[Moelf]

#before 
julia> @b AwkwardArray.RecordArray((;x=AwkwardArray.PrimitiveArray([1,2,3])))
126.453 ns (7 allocs: 272 bytes)

#after
julia> @b AwkwardArray.RecordArray((;x=AwkwardArray.PrimitiveArray([1,2,3])))
18.722 ns (3 allocs: 144 bytes)

[codecov]

Codecov Report

All modified and coverable lines are covered by tests ✅

Project coverage is 76.09%. Comparing base (6ba1c4a) to head (68a24a2).
Report is 1 commits behind head on main.

Additional details and impacted files

@@           Coverage Diff           @@
##             main     #114   +/-   ##
=======================================
  Coverage   76.09%   76.09%           
=======================================
  Files           5        5           
  Lines        1740     1740           
=======================================
  Hits         1324     1324           
  Misses        416      416           

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