tests: remove the custom run-tests.py
This test-runners is a copy from the Mercurial one and slowly drift out of sync.
Use the Mercurial's core test runners instead.
Initialsetup$.$TESTDIR/_exc-util.sh===B.7Pruneonnon-targetedcommonchangeset===....{{{..⊗B..|..◕A..|..●O..}}}....Markerexistfrom:....*B(prune)....Commandrun:....*hgpush-rO........*hgpush....Expectedexchange:....*ø.......*B(prune)$setupreposB.7creatingtestrepofortestcaseB.7-pulldest-main-pushdestcdinto`main`andproceedwithenvsetup$cdmain$mkcommitA$hgpush-q../pushdest$hgpush-q../pulldest$mkcommitB$hgprune-qd'0 0'.$hglog-G--hiddenxf6fbb35d8ac9(draft):B|@f5bc6836db60(draft):A|oa9bdc8b26820(public):O$hgdebugobsoletef6fbb35d8ac958bbe70035e4c789c18471cdc0af0{f5bc6836db60e308a17ba08bf050154ba9c4fad7}(ThuJan0100:00:001970+0000){'user':'test'}$cd..$cd..ActualTest-------------------------------------$dotestB.7O##RunningtestcaseB.7 # testing echange of "O" (a9bdc8b26820) ## initial state # obstore: mainf6fbb35d8ac958bbe70035e4c789c18471cdc0af0{f5bc6836db60e308a17ba08bf050154ba9c4fad7}(ThuJan0100:00:001970+0000){'user':'test'} # obstore: pushdest # obstore: pulldest ## pushing "O" from main to pushdestpushingtopushdestsearchingforchangesnochangesfound##postpushstate#obstore:mainf6fbb35d8ac958bbe70035e4c789c18471cdc0af0{f5bc6836db60e308a17ba08bf050154ba9c4fad7}(ThuJan0100:00:001970+0000){'user':'test'} # obstore: pushdest # obstore: pulldest ## pulling "a9bdc8b26820" from main into pulldestpullingfrommainnochangesfound##postpullstate#obstore:mainf6fbb35d8ac958bbe70035e4c789c18471cdc0af0{f5bc6836db60e308a17ba08bf050154ba9c4fad7}(ThuJan0100:00:001970+0000){'user':'test'} # obstore: pushdest # obstore: pulldest