Remove duplicate defs in win32/window.go

[AlbinoDrought]

Introduced in 70c484f

Until these duplicate defs are removed, bleeding edge Windows build fail with:

  Build command: go build -trimpath -tags desktop,production -ldflags -w -s -H windowsgui -o /app/build/bin/app.exe
  Environment: HOSTNAME=e7e5205f866a PATH=/go/bin:/usr/local/go/bin:/usr/local/sbin:/usr/local/bin:/usr/sbin:/usr/bin:/sbin:/bin GOPATH=/go PWD=/app GOLANG_VERSION=1.19 GOOS=windows GOARCH=amd64
go list error: exit status 2: # github.com/wailsapp/wails/v2/internal/frontend/desktop/windows/win32
wails/v2/internal/frontend/desktop/windows/win32/window.go:18:2: WS_MINIMIZE redeclared in this block
	wails/v2/internal/frontend/desktop/windows/win32/window.go:16:2: other declaration of WS_MINIMIZE
wails/v2/internal/frontend/desktop/windows/win32/window.go:146:6: IsWindowMinimised redeclared in this block
	wails/v2/internal/frontend/desktop/windows/win32/window.go:120:6: other declaration of IsWindowMinimised

[leaanthony]

Thanks for this! Bad merge 😱