Remove MSVC compiler warning suppressions in KeyVault

The code within the `mocked_transport_adapter_test.hpp` file, specifically within the `Azure::Security::KeyVault::Keys` namespace, has been updated. The `#if defined(_MSC_VER)` preprocessor directive along with its associated `#pragma warning(push)` and `#pragma warning(disable : 4996)` directives have been removed. The corresponding `#pragma warning(pop)` directive has also been removed. The lines of code that were between these preprocessor directives remain unchanged. These changes remove specific compiler warning suppressions for MSVC compilers, but do not alter the functional behavior of the code.

sdk/keyvault/azure-security-keyvault-keys/test/ut/mocked_transport_adapter_test.hpp

@@ -91,15 +91,8 @@ namespace Azure { namespace Security { namespace KeyVault { namespace Keys { nam
         keyType = "oct";
       }
 
-#if defined(_MSC_VER)
-#pragma warning(push)
-#pragma warning(disable : 4996)
-#endif
       result += fakeKey;
       result += keyType.c_str();
-#if defined(_MSC_VER)
-#pragma warning(pop)
-#endif
 
       return result.c_str();
     }