Docs: Remove "-dev" version in versionchanged
Docs: Remove "-dev" version in versionchanged

I haven't found this version syntax used previously + it's easier to replace e.g. `.. versionchanged:: 1.10.1` when releasing.
manthansharma/kivy,matham/kivy,rnixx/kivy,rnixx/kivy,manthansharma/kivy,jegger/kivy,akshayaurora/kivy,inclement/kivy,inclement/kivy,jkankiewicz/kivy,bionoid/kivy,KeyWeeUsr/kivy,matham/kivy,Cheaterman/kivy,kivy/kivy,bionoid/kivy,jegger/kivy,rnixx/kivy,akshayaurora/kivy,KeyWeeUsr/kivy,manthansharma/kivy,Cheaterman/kivy,bionoid/kivy,jegger/kivy,jkankiewicz/kivy,KeyWeeUsr/kivy,jegger/kivy,matham/kivy,LogicalDash/kivy,Cheaterman/kivy,manthansharma/kivy,Cheaterman/kivy,inclement/kivy,jkankiewicz/kivy,LogicalDash/kivy,LogicalDash/kivy,akshayaurora/kivy,LogicalDash/kivy,kivy/kivy,kivy/kivy,matham/kivy,bionoid/kivy,KeyWeeUsr/kivy,jkankiewicz/kivy