Fix: fix ByteMaskedArray.simplify_optiontype()

[agoose77]

Currently ByteMaskedArray.simplify_optiontype() has a few typos that mean it raises an AttributeError instead of returning a simplified layout.

[codecov]

Codecov Report

Merging #1259 (56312ea) into main (ab65e20) will increase coverage by 0.24%.
The diff coverage is 60.78%.

Impacted Files	Coverage Δ
src/awkward/_v2/__init__.py	100.00% <ø> (ø)
src/awkward/_v2/_connect/numpy.py	58.63% <0.00%> (+0.17%)	⬆️
src/awkward/_v2/behaviors/string.py	71.42% <ø> (+16.88%)	⬆️
src/awkward/_v2/contents/__init__.py	100.00% <ø> (ø)
src/awkward/_v2/contents/emptyarray.py	69.36% <0.00%> (-0.18%)	⬇️
src/awkward/_v2/contents/indexedarray.py	60.64% <0.00%> (-0.10%)	⬇️
src/awkward/_v2/contents/indexedoptionarray.py	85.40% <0.00%> (+0.15%)	⬆️
src/awkward/_v2/contents/listarray.py	87.95% <0.00%> (+0.21%)	⬆️
src/awkward/_v2/contents/listoffsetarray.py	79.68% <0.00%> (+0.12%)	⬆️
src/awkward/_v2/contents/regulararray.py	82.85% <0.00%> (+0.18%)	⬆️
... and 146 more

[jpivarski]

Thanks for fixing this; these are unquestionably bugs.