windows: delete TestGetKeyboardLayout

According to
https://learn.microsoft.com/en-us/windows/win32/api/winuser/nf-winuser-getforegroundwindow
GetForegroundWindow can return nil in some circumstances. So
GetForegroundWindow cannot be used in the TestGetKeyboardLayout.
Just delete the test for now.

Fixes golang/go#68671

Change-Id: I7e05ac2f19b1a6310a3f7f690c6d02b0d1f5571e
Reviewed-on: https://go-review.googlesource.com/c/sys/+/602335
Reviewed-by: Cherry Mui <cherryyz@google.com>
Reviewed-by: David Chase <drchase@google.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Ayman Bagabas <ayman.bagabas@gmail.com>

windows/syscall_windows_test.go

@@ -1438,17 +1438,6 @@ uintptr_t beep(void) {
 	}
 }
 
-func TestGetKeyboardLayout(t *testing.T) {
-	fg := windows.GetForegroundWindow()
-	tid, err := windows.GetWindowThreadProcessId(fg, nil)
-	if err != nil {
-		t.Fatalf("GetWindowThreadProcessId failed: %v", err)
-	}
-
-	// We don't care about the result, just that it doesn't crash.
-	_ = windows.GetKeyboardLayout(tid)
-}
-
 func TestToUnicodeEx(t *testing.T) {
 	var utf16Buf [16]uint16