C#: Adjust options to point to the stub location within the checked out codeql repo.

Author: michaelnebel

csharp/test/security/CWE-942/options

@@ -1,4 +1,4 @@
 semmle-extractor-options: /nostdlib /noconfig
-semmle-extractor-options: --load-sources-from-project:${testdir}/../../resources/stubs/_frameworks/Microsoft.NETCore.App/Microsoft.NETCore.App.csproj
-semmle-extractor-options: --load-sources-from-project:../../resources/stubs/_frameworks/Microsoft.AspNetCore.App/Microsoft.AspNetCore.App.csproj
+semmle-extractor-options: --load-sources-from-project:${testdir}/../../../../codeql/csharp/ql/test/resources/stubs/_frameworks/Microsoft.NETCore.App/Microsoft.NETCore.App.csproj
+semmle-extractor-options: --load-sources-from-project:${testdir}/../../../../codeql/csharp/ql/test/resources/stubs/_frameworks/Microsoft.AspNetCore.App/Microsoft.AspNetCore.App.csproj