feat!: revert breaking component of asarray PR

[agoose77]

This PR reverts the breaking parts of #2740 to introduce a deprecation period.

[codecov]

Codecov Report

Merging #2752 (e8fff34) into main (0e27b90) will decrease coverage by 0.01%.
Report is 2 commits behind head on main.
The diff coverage is 73.17%.

Additional details and impacted files

Files	Coverage Δ
src/awkward/contents/indexedarray.py	78.99% <100.00%> (ø)
src/awkward/contents/indexedoptionarray.py	88.48% <100.00%> (ø)
src/awkward/contents/unmaskedarray.py	74.40% <100.00%> (ø)
src/awkward/operations/ak_flatten.py	93.47% <100.00%> (ø)
src/awkward/operations/ak_run_lengths.py	90.12% <100.00%> (ø)
src/awkward/operations/ak_to_dataframe.py	90.55% <100.00%> (-0.08%)	⬇️
src/awkward/operations/ak_to_categorical.py	93.54% <50.00%> (ø)
src/awkward/operations/ak_unflatten.py	96.15% <75.00%> (ø)
src/awkward/contents/emptyarray.py	75.12% <50.00%> (-0.50%)	⬇️
src/awkward/contents/numpyarray.py	91.22% <50.00%> (-0.32%)	⬇️
... and 1 more

... and 1 file with indirect coverage changes

[jpivarski]

Index.__array__ would need the same deprecation period.