MAINT: add .theia/ to .gitignore (#13668)
MAINT: add .theia/ to .gitignore (#13668)

This avoids having an untracked file in Gitpod workspaces

[ci skip]
andyfaff/scipy,e-q/scipy,endolith/scipy,anntzer/scipy,rgommers/scipy,endolith/scipy,endolith/scipy,andyfaff/scipy,WarrenWeckesser/scipy,tylerjereddy/scipy,anntzer/scipy,WarrenWeckesser/scipy,scipy/scipy,zerothi/scipy,Eric89GXL/scipy,e-q/scipy,mdhaber/scipy,andyfaff/scipy,zerothi/scipy,Stefan-Endres/scipy,ilayn/scipy,grlee77/scipy,grlee77/scipy,mdhaber/scipy,endolith/scipy,tylerjereddy/scipy,WarrenWeckesser/scipy,tylerjereddy/scipy,scipy/scipy,ilayn/scipy,WarrenWeckesser/scipy,Eric89GXL/scipy,Eric89GXL/scipy,rgommers/scipy,e-q/scipy,perimosocordiae/scipy,anntzer/scipy,WarrenWeckesser/scipy,mdhaber/scipy,perimosocordiae/scipy,zerothi/scipy,rgommers/scipy,zerothi/scipy,Eric89GXL/scipy,Stefan-Endres/scipy,matthew-brett/scipy,andyfaff/scipy,ilayn/scipy,andyfaff/scipy,matthew-brett/scipy,vigna/scipy,perimosocordiae/scipy,e-q/scipy,Stefan-Endres/scipy,Eric89GXL/scipy,tylerjereddy/scipy,rgommers/scipy,scipy/scipy,rgommers/scipy,scipy/scipy,perimosocordiae/scipy,ilayn/scipy,Eric89GXL/scipy,endolith/scipy,grlee77/scipy,anntzer/scipy,perimosocordiae/scipy,anntzer/scipy,ilayn/scipy,endolith/scipy,zerothi/scipy,scipy/scipy,perimosocordiae/scipy,mdhaber/scipy,mdhaber/scipy,matthew-brett/scipy,vigna/scipy,Stefan-Endres/scipy,zerothi/scipy,scipy/scipy,Stefan-Endres/scipy,vigna/scipy,mdhaber/scipy,anntzer/scipy,grlee77/scipy,andyfaff/scipy,matthew-brett/scipy,vigna/scipy,grlee77/scipy,ilayn/scipy,WarrenWeckesser/scipy,e-q/scipy,tylerjereddy/scipy,matthew-brett/scipy,Stefan-Endres/scipy,vigna/scipy