Auto merge of #12020 - crepererum:fix/shebang, r=aneeshusa
Auto merge of #12020 - crepererum:fix/shebang, r=aneeshusa

Add shebang to Linux runservo.sh

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Shebang is missing and therefore `./runservo.sh` does not work under some environments.

I've chosen to use `/usr/bin/env sh` instead of `/bin/sh` or `/usr/bin/sh` to auto-select the right `sh` executable depending on the environment.

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<!-- Thank you for contributing to Servo! Please replace each `[ ]` by `[X]` when the step is complete, and replace `__` with appropriate data: -->
- [X] `./mach build -d` does not report any errors
- [X] `./mach test-tidy` does not report any errors

<!-- Either: -->
- [X] These changes do not require tests because it does not affect servo itself but rather the resulting package under some environments.

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