Auto merge of #16338 - Wafflespeanut:byte, r=jdm
Auto merge of #16338 - Wafflespeanut:byte, r=jdm

Disable bytecode generation in mach

Recently, [@]froydnj had some trouble with `mach`, and after half an hour of struggle, a simple `git clean` and `git reset --hard` seemed to fix the issue. Apparently, sometimes (though I'm not sure when, and I don't even have a convincing argument), the changes to `mach` scripts don't really seem to reflect on the related bytecode files (when it absolutely should've!).

Having bytecode files is just a matter of optimization (i.e., we don't have to compile the scripts again), but when it comes to our simple build system, "not having them" doesn't add a great overhead. So, we could just disable their creation to avoid such issues in the future.

Existing users can do `find ./python -name '*.pyc' -delete` for a cleanup (and maybe remove the `python/_virtualenv` directory too, though not necessary)

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CJ8664/servo,notriddle/servo,paulrouget/servo,nnethercote/servo,SimonSapin/servo,thiagopnts/servo,rnestler/servo,dsandeephegde/servo,larsbergstrom/servo,paulrouget/servo,canaltinova/servo,paulrouget/servo,saneyuki/servo,cbrewster/servo,ConnorGBrewster/servo,dati91/servo,peterjoel/servo,larsbergstrom/servo,eddyb/servo,saneyuki/servo,emilio/servo,splav/servo,CJ8664/servo,paulrouget/servo,KiChjang/servo,ConnorGBrewster/servo,jimberlage/servo,sadmansk/servo,SimonSapin/servo,thiagopnts/servo,fiji-flo/servo,avadacatavra/servo,szeged/servo,DominoTree/servo,DominoTree/servo,nnethercote/servo,emilio/servo,peterjoel/servo,SimonSapin/servo,dati91/servo,saneyuki/servo,splav/servo,avadacatavra/servo,rnestler/servo,anthgur/servo,canaltinova/servo,jimberlage/servo,jimberlage/servo,sadmansk/servo,CJ8664/servo,larsbergstrom/servo,KiChjang/servo,canaltinova/servo,pyfisch/servo,peterjoel/servo,mbrubeck/servo,rnestler/servo,larsbergstrom/servo,szeged/servo,dsandeephegde/servo,larsbergstrom/servo,eddyb/servo,nnethercote/servo,sadmansk/servo,emilio/servo,jimberlage/servo,peterjoel/servo,fiji-flo/servo,emilio/servo,pyfisch/servo,mattnenterprise/servo,KiChjang/servo,mattnenterprise/servo,anthgur/servo,KiChjang/servo,dati91/servo,rnestler/servo,SimonSapin/servo,szeged/servo,jimberlage/servo,pyfisch/servo,fiji-flo/servo,anthgur/servo,avadacatavra/servo,splav/servo,notriddle/servo,saneyuki/servo,eddyb/servo,rnestler/servo,ConnorGBrewster/servo,splav/servo,dsandeephegde/servo,splav/servo,mbrubeck/servo,canaltinova/servo,anthgur/servo,cbrewster/servo,paulrouget/servo,upsuper/servo,eddyb/servo,splav/servo,DominoTree/servo,avadacatavra/servo,thiagopnts/servo,pyfisch/servo,KiChjang/servo,jimberlage/servo,upsuper/servo,larsbergstrom/servo,splav/servo,saneyuki/servo,eddyb/servo,DominoTree/servo,saneyuki/servo,emilio/servo,thiagopnts/servo,paulrouget/servo,canaltinova/servo,notriddle/servo,notriddle/servo,anthgur/servo,szeged/servo,pyfisch/servo,thiagopnts/servo,notriddle/servo,szeged/servo,avadacatavra/servo,avadacatavra/servo,larsbergstrom/servo,notriddle/servo,ConnorGBrewster/servo,KiChjang/servo,paulrouget/servo,upsuper/servo,dsandeephegde/servo,eddyb/servo,jimberlage/servo,emilio/servo,mattnenterprise/servo,szeged/servo,sadmansk/servo,nnethercote/servo,ConnorGBrewster/servo,saneyuki/servo,SimonSapin/servo,canaltinova/servo,DominoTree/servo,cbrewster/servo,nnethercote/servo,upsuper/servo,pyfisch/servo,rnestler/servo,dati91/servo,KiChjang/servo,cbrewster/servo,fiji-flo/servo,canaltinova/servo,szeged/servo,splav/servo,peterjoel/servo,dati91/servo,mbrubeck/servo,notriddle/servo,upsuper/servo,thiagopnts/servo,anthgur/servo,nnethercote/servo,anthgur/servo,nnethercote/servo,mattnenterprise/servo,jimberlage/servo,dsandeephegde/servo,KiChjang/servo,rnestler/servo,saneyuki/servo,dsandeephegde/servo,emilio/servo,mbrubeck/servo,CJ8664/servo,sadmansk/servo,avadacatavra/servo,szeged/servo,paulrouget/servo,dati91/servo,mattnenterprise/servo,larsbergstrom/servo,DominoTree/servo,SimonSapin/servo,DominoTree/servo,notriddle/servo,SimonSapin/servo,DominoTree/servo,dati91/servo,KiChjang/servo,DominoTree/servo,notriddle/servo,cbrewster/servo,peterjoel/servo,eddyb/servo,CJ8664/servo,notriddle/servo,avadacatavra/servo,rnestler/servo,fiji-flo/servo,splav/servo,mattnenterprise/servo,emilio/servo,paulrouget/servo,mbrubeck/servo,mattnenterprise/servo,upsuper/servo,pyfisch/servo,peterjoel/servo,cbrewster/servo,jimberlage/servo,paulrouget/servo,mbrubeck/servo,mattnenterprise/servo,pyfisch/servo,nnethercote/servo,DominoTree/servo,thiagopnts/servo,larsbergstrom/servo,SimonSapin/servo,pyfisch/servo,ConnorGBrewster/servo,CJ8664/servo,peterjoel/servo,splav/servo,pyfisch/servo,saneyuki/servo,dsandeephegde/servo,sadmansk/servo,upsuper/servo,ConnorGBrewster/servo,eddyb/servo,emilio/servo,cbrewster/servo,peterjoel/servo,nnethercote/servo,szeged/servo,CJ8664/servo,upsuper/servo,emilio/servo,sadmansk/servo,cbrewster/servo,sadmansk/servo,fiji-flo/servo,fiji-flo/servo,szeged/servo,mbrubeck/servo,nnethercote/servo,saneyuki/servo,larsbergstrom/servo,thiagopnts/servo,ConnorGBrewster/servo,dsandeephegde/servo,KiChjang/servo,anthgur/servo,canaltinova/servo,CJ8664/servo,fiji-flo/servo,mbrubeck/servo,peterjoel/servo,dati91/servo