contrib: fix implicit function decleration in win symbol check

```bash
test3.c: In function 'main':
test3.c:6:21: warning: implicit declaration of function 'CoFreeUnusedLibrariesEx' [-Wimplicit-function-declaration]
    6 |                     CoFreeUnusedLibrariesEx(0,0);
```

contrib/devtools/test-symbol-check.py

@@ -187,7 +187,7 @@ class TestSymbolChecks(unittest.TestCase):
         executable = 'test3.exe'
         with open(source, 'w', encoding="utf8") as f:
             f.write('''
-                #include <windows.h>
+                #include <combaseapi.h>
 
                 int main()
                 {