Windows: Drop support for obsolete MinGW
Windows: Drop support for obsolete MinGW

The version we support is MinGW-w64: https://sourceforge.net/p/mingw-w64
The old original MinGW from which it was forked (https://sourceforge.net/projects/mingw),
is no longer maintained and useless for us.

Fixes #10396.

Valentactive/godot,n-pigeon/godot,ageazrael/godot,Faless/godot,ZuBsPaCe/godot,guilhermefelipecgs/godot,NateWardawg/godot,Valentactive/godot,n-pigeon/godot,Paulloz/godot,Faless/godot,okamstudio/godot,FateAce/godot,FateAce/godot,MarianoGnu/godot,Valentactive/godot,DmitriySalnikov/godot,n-pigeon/godot,MarianoGnu/godot,BastiaanOlij/godot,Shockblast/godot,jejung/godot,pkowal1982/godot,NateWardawg/godot,NateWardawg/godot,ZuBsPaCe/godot,Paulloz/godot,guilhermefelipecgs/godot,akien-mga/godot,n-pigeon/godot,ageazrael/godot,godotengine/godot,Brickcaster/godot,Shockblast/godot,firefly2442/godot,FateAce/godot,Zylann/godot,NateWardawg/godot,guilhermefelipecgs/godot,okamstudio/godot,firefly2442/godot,groud/godot,Faless/godot,guilhermefelipecgs/godot,vkbsb/godot,firefly2442/godot,MarianoGnu/godot,mcanders/godot,pkowal1982/godot,vnen/godot,Faless/godot,vkbsb/godot,josempans/godot,n-pigeon/godot,honix/godot,RandomShaper/godot,okamstudio/godot,FateAce/godot,Zylann/godot,pkowal1982/godot,Paulloz/godot,godotengine/godot,vnen/godot,mcanders/godot,Faless/godot,Shockblast/godot,zicklag/godot,zicklag/godot,ZuBsPaCe/godot,josempans/godot,ex/godot,ZuBsPaCe/godot,jejung/godot,BastiaanOlij/godot,pkowal1982/godot,n-pigeon/godot,okamstudio/godot,ex/godot,akien-mga/godot,groud/godot,jejung/godot,Valentactive/godot,Zylann/godot,vnen/godot,Brickcaster/godot,Brickcaster/godot,Faless/godot,firefly2442/godot,mcanders/godot,Faless/godot,guilhermefelipecgs/godot,groud/godot,okamstudio/godot,firefly2442/godot,Paulloz/godot,ageazrael/godot,pkowal1982/godot,pkowal1982/godot,sanikoyes/godot,DmitriySalnikov/godot,zicklag/godot,ageazrael/godot,okamstudio/godot,DmitriySalnikov/godot,ZuBsPaCe/godot,MarianoGnu/godot,godotengine/godot,firefly2442/godot,okamstudio/godot,Shockblast/godot,godotengine/godot,sanikoyes/godot,honix/godot,vkbsb/godot,Brickcaster/godot,sanikoyes/godot,Valentactive/godot,groud/godot,RandomShaper/godot,vnen/godot,ex/godot,Zylann/godot,FateAce/godot,Shockblast/godot,ageazrael/godot,BastiaanOlij/godot,Paulloz/godot,firefly2442/godot,DmitriySalnikov/godot,Valentactive/godot,jejung/godot,BastiaanOlij/godot,Brickcaster/godot,NateWardawg/godot,mcanders/godot,okamstudio/godot,guilhermefelipecgs/godot,BastiaanOlij/godot,BastiaanOlij/godot,mcanders/godot,DmitriySalnikov/godot,vnen/godot,MarianoGnu/godot,RandomShaper/godot,ex/godot,ex/godot,MarianoGnu/godot,josempans/godot,godotengine/godot,josempans/godot,akien-mga/godot,Brickcaster/godot,jejung/godot,pkowal1982/godot,godotengine/godot,vnen/godot,akien-mga/godot,MarianoGnu/godot,groud/godot,sanikoyes/godot,NateWardawg/godot,honix/godot,Valentactive/godot,zicklag/godot,Faless/godot,akien-mga/godot,Valentactive/godot,josempans/godot,josempans/godot,ZuBsPaCe/godot,okamstudio/godot,pkowal1982/godot,sanikoyes/godot,akien-mga/godot,honix/godot,MarianoGnu/godot,NateWardawg/godot,akien-mga/godot,vkbsb/godot,ex/godot,FateAce/godot,mcanders/godot,ZuBsPaCe/godot,RandomShaper/godot,vkbsb/godot,Zylann/godot,vkbsb/godot,DmitriySalnikov/godot,n-pigeon/godot,sanikoyes/godot,DmitriySalnikov/godot,jejung/godot,vnen/godot,vnen/godot,akien-mga/godot,Shockblast/godot,guilhermefelipecgs/godot,zicklag/godot,sanikoyes/godot,honix/godot,Zylann/godot,honix/godot,Shockblast/godot,BastiaanOlij/godot,RandomShaper/godot,josempans/godot,guilhermefelipecgs/godot,ageazrael/godot,vkbsb/godot,RandomShaper/godot,Brickcaster/godot,godotengine/godot,josempans/godot,Paulloz/godot,sanikoyes/godot,godotengine/godot,BastiaanOlij/godot,Zylann/godot,Paulloz/godot,ZuBsPaCe/godot,Zylann/godot,okamstudio/godot,firefly2442/godot,NateWardawg/godot,groud/godot,ex/godot,NateWardawg/godot,zicklag/godot,ageazrael/godot,Shockblast/godot,RandomShaper/godot,vkbsb/godot,ex/godot