[feat] remove gtk init

Is not needed and is breaking our tests.

dlgs_linux.go

@@ -9,10 +9,6 @@ import (
 	"github.com/gotk3/gotk3/gtk"
 )
 
-func init() {
-	gtk.Init(nil)
-}
-
 func closeDialog(dlg *gtk.Dialog) {
 	dlg.Destroy()
 }