TST: ujson tests are not being run (#16499) (#16500)
TST: ujson tests are not being run (#16499) (#16500)

closes #16499 
pandas-dev/pandas,dsm054/pandas,nmartensen/pandas,linebp/pandas,Winand/pandas,harisbal/pandas,pandas-dev/pandas,pandas-dev/pandas,amolkahat/pandas,datapythonista/pandas,winklerand/pandas,nmartensen/pandas,harisbal/pandas,jreback/pandas,Winand/pandas,DGrady/pandas,toobaz/pandas,zfrenchee/pandas,louispotok/pandas,linebp/pandas,harisbal/pandas,toobaz/pandas,TomAugspurger/pandas,kdebrab/pandas,jmmease/pandas,cython-testbed/pandas,jmmease/pandas,zfrenchee/pandas,Winand/pandas,dsm054/pandas,datapythonista/pandas,datapythonista/pandas,GuessWhoSamFoo/pandas,TomAugspurger/pandas,toobaz/pandas,jmmease/pandas,jmmease/pandas,gfyoung/pandas,GuessWhoSamFoo/pandas,pandas-dev/pandas,jreback/pandas,kdebrab/pandas,rs2/pandas,cbertinato/pandas,gfyoung/pandas,zfrenchee/pandas,GuessWhoSamFoo/pandas,Winand/pandas,nmartensen/pandas,gfyoung/pandas,gfyoung/pandas,pratapvardhan/pandas,zfrenchee/pandas,TomAugspurger/pandas,louispotok/pandas,MJuddBooth/pandas,cython-testbed/pandas,cbertinato/pandas,kdebrab/pandas,Winand/pandas,winklerand/pandas,jorisvandenbossche/pandas,GuessWhoSamFoo/pandas,jmmease/pandas,nmartensen/pandas,louispotok/pandas,pratapvardhan/pandas,datapythonista/pandas,MJuddBooth/pandas,MJuddBooth/pandas,jreback/pandas,jorisvandenbossche/pandas,pratapvardhan/pandas,MJuddBooth/pandas,TomAugspurger/pandas,gfyoung/pandas,dsm054/pandas,linebp/pandas,DGrady/pandas,rs2/pandas,toobaz/pandas,winklerand/pandas,toobaz/pandas,pratapvardhan/pandas,winklerand/pandas,jorisvandenbossche/pandas,pratapvardhan/pandas,kdebrab/pandas,cython-testbed/pandas,cbertinato/pandas,linebp/pandas,jreback/pandas,rs2/pandas,harisbal/pandas,harisbal/pandas,cython-testbed/pandas,winklerand/pandas,cbertinato/pandas,nmartensen/pandas,DGrady/pandas,MJuddBooth/pandas,cbertinato/pandas,jmmease/pandas,DGrady/pandas,zfrenchee/pandas,winklerand/pandas,GuessWhoSamFoo/pandas,dsm054/pandas,jorisvandenbossche/pandas,DGrady/pandas,Winand/pandas,linebp/pandas,amolkahat/pandas,amolkahat/pandas,linebp/pandas,amolkahat/pandas,kdebrab/pandas,dsm054/pandas,DGrady/pandas,amolkahat/pandas,nmartensen/pandas,cython-testbed/pandas,rs2/pandas,louispotok/pandas,louispotok/pandas,jreback/pandas