Mono/C#: Fix MinGW build not supporting `.lib` libraries
Mono/C#: Fix MinGW build not supporting `.lib` libraries

MinGW should support both its own format `.a` and MSVC's format `.lib`,
but Mono's module was only using the former. With this change it's now
possible to build with MinGW and link the official Mono for Windows
which is built with MSVC.

akien-mga/godot,Shockblast/godot,DmitriySalnikov/godot,sanikoyes/godot,ZuBsPaCe/godot,akien-mga/godot,honix/godot,ZuBsPaCe/godot,godotengine/godot,vkbsb/godot,vnen/godot,MarianoGnu/godot,DmitriySalnikov/godot,BastiaanOlij/godot,guilhermefelipecgs/godot,firefly2442/godot,BastiaanOlij/godot,Shockblast/godot,DmitriySalnikov/godot,akien-mga/godot,MarianoGnu/godot,vnen/godot,Shockblast/godot,Valentactive/godot,guilhermefelipecgs/godot,Shockblast/godot,josempans/godot,guilhermefelipecgs/godot,BastiaanOlij/godot,guilhermefelipecgs/godot,Valentactive/godot,Valentactive/godot,josempans/godot,vkbsb/godot,godotengine/godot,sanikoyes/godot,Valentactive/godot,Faless/godot,Valentactive/godot,firefly2442/godot,DmitriySalnikov/godot,akien-mga/godot,guilhermefelipecgs/godot,pkowal1982/godot,Valentactive/godot,vnen/godot,honix/godot,Zylann/godot,Zylann/godot,sanikoyes/godot,pkowal1982/godot,vnen/godot,josempans/godot,MarianoGnu/godot,ZuBsPaCe/godot,honix/godot,sanikoyes/godot,Zylann/godot,Shockblast/godot,pkowal1982/godot,akien-mga/godot,godotengine/godot,godotengine/godot,firefly2442/godot,Paulloz/godot,honix/godot,MarianoGnu/godot,Shockblast/godot,vnen/godot,sanikoyes/godot,godotengine/godot,pkowal1982/godot,godotengine/godot,josempans/godot,firefly2442/godot,josempans/godot,DmitriySalnikov/godot,Faless/godot,vkbsb/godot,godotengine/godot,josempans/godot,Paulloz/godot,MarianoGnu/godot,Zylann/godot,Zylann/godot,guilhermefelipecgs/godot,firefly2442/godot,ZuBsPaCe/godot,sanikoyes/godot,pkowal1982/godot,Faless/godot,vkbsb/godot,BastiaanOlij/godot,Zylann/godot,Paulloz/godot,godotengine/godot,vkbsb/godot,guilhermefelipecgs/godot,guilhermefelipecgs/godot,Valentactive/godot,BastiaanOlij/godot,honix/godot,vnen/godot,akien-mga/godot,BastiaanOlij/godot,MarianoGnu/godot,Shockblast/godot,Faless/godot,BastiaanOlij/godot,Paulloz/godot,sanikoyes/godot,firefly2442/godot,Paulloz/godot,pkowal1982/godot,DmitriySalnikov/godot,Paulloz/godot,firefly2442/godot,ZuBsPaCe/godot,DmitriySalnikov/godot,josempans/godot,BastiaanOlij/godot,ZuBsPaCe/godot,vnen/godot,Valentactive/godot,MarianoGnu/godot,MarianoGnu/godot,Faless/godot,Paulloz/godot,Faless/godot,Shockblast/godot,vkbsb/godot,pkowal1982/godot,ZuBsPaCe/godot,vnen/godot,sanikoyes/godot,firefly2442/godot,pkowal1982/godot,ZuBsPaCe/godot,honix/godot,vkbsb/godot,Zylann/godot,Faless/godot,Zylann/godot,vkbsb/godot,akien-mga/godot,josempans/godot,Faless/godot,akien-mga/godot