Remove PYTHON-PREPROCESSING-REQUIRED lines
Remove PYTHON-PREPROCESSING-REQUIRED lines

This line forces [] to use Python-Preprocessing, although the BUILD file
doesn't need it. It makes the builds slower and it is deprecated.
[]

Tested:
    [] train for global presubmit queue
    []    Some tests failed; test failures are believed to be unrelated to this CL
-------------
Created by MOE: https://github.com/google/moe
MOE_MIGRATED_REVID=101014848

nathancomstock/closure-templates,SerkanSipahi/closure-templates,rpatil26/closure-templates,SerkanSipahi/closure-templates,iacdingping/closure-templates,google/closure-templates,nathancomstock/closure-templates,iacdingping/closure-templates,rgpower/closure-templates,rpatil26/closure-templates,SerkanSipahi/closure-templates,atul-bhouraskar/closure-templates,yext/closure-templates,google/closure-templates,rgpower/closure-templates,yext/closure-templates,atul-bhouraskar/closure-templates,atul-bhouraskar/closure-templates,iacdingping/closure-templates,yext/closure-templates,SerkanSipahi/closure-templates,Medium/closure-templates,rgpower/closure-templates,google/closure-templates,google/closure-templates,iacdingping/closure-templates,google/closure-templates,nathancomstock/closure-templates,nathancomstock/closure-templates,Medium/closure-templates,yext/closure-templates,Medium/closure-templates,rgpower/closure-templates,Medium/closure-templates,Medium/closure-templates,atul-bhouraskar/closure-templates,rpatil26/closure-templates,rpatil26/closure-templates