patch 9.0.0436: CI: running tests in parallel causes flakiness

Problem:    CI: running tests in parallel causes flakiness.
Solution:   Reorganize the MS-Windows runs. (Ken Takata, closes #11101)
diff --git a/src/os_win32.c b/src/os_win32.c
index d936e4f..af2622c 100644
--- a/src/os_win32.c
+++ b/src/os_win32.c
@@ -2834,7 +2834,11 @@
 	return;
 
     // Extract the first icon contained in the Vim executable.
-    if (mch_icon_load((HANDLE *)&g_hVimIcon) == FAIL || g_hVimIcon == NULL)
+    if (
+# ifdef FEAT_LIBCALL
+	    mch_icon_load((HANDLE *)&g_hVimIcon) == FAIL ||
+# endif
+	    g_hVimIcon == NULL)
 	g_hVimIcon = ExtractIcon(NULL, (LPCSTR)exe_name, 0);
     if (g_hVimIcon != NULL)
 	g_fCanChangeIcon = TRUE;