[core:os/os2] Keep -vet happy.

core/os/os2/file_util.odin

@@ -1,7 +1,6 @@
 package os2
 
 import "core:mem"
-import "core:io"
 import "core:strconv"
 import "core:unicode/utf8"
 

core/os/os2/heap_windows.odin

@@ -1,7 +1,6 @@
 //+private
 package os2
 
-import "core:runtime"
 import "core:mem"
 import win32 "core:sys/windows"