BLD: parsers.pyx seems to be re-running on each commit

[jreback]

for some reason parsers.pyx (and the generated parsers.c) seems to be rebuilding on each commit (whether anything changed or not).

cc @gfyoung @jbrockmendel

maybe something odd in setup.py

[gfyoung]

Weird...even rebuilds parsers.pyx when I install on the same commit several times...

[gfyoung]

maybe something odd in setup.py

Indeed, it is. git bisect indicates that #22469 forgot to drop numpy_helper.h from the dependencies list of _libs/parsers, as the file became non-existent.