Fix preview in file dialog
Fix preview in file dialog

If the preview is already cached, queue_ressource_preview calls
_thumbnail_done immediately, so preview_waiting is never set to false
again. The progress wheel isn't rendered, because the WaitPreview icons
don't exist. This should probably be Progress.
Fixes #25749

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