zig build system: delete ./build file on success
zig build system: delete ./build file on success

see #204

zig-lang/zig,andrewrk/zig,raulgrell/zig,zig-lang/zig,raulgrell/zig,raulgrell/zig,raulgrell/zig,Dimenus/zig,zig-lang/zig,Dimenus/zig,raulgrell/zig,andrewrk/zig,Dimenus/zig