Disable flakey auth test on Linux (#1119)

Author: a-maurice

auth/tests/CMakeLists.txt

@@ -159,18 +159,20 @@ firebase_cpp_cc_test(
     firebase_testing
 )
 
-firebase_cpp_cc_test(
-  firebase_auth_user_desktop_test
-  SOURCES
-    desktop/user_desktop_test.cc
-  DEPENDS
-    firebase_app_for_testing
-    firebase_auth
-    firebase_auth_desktop_test_util
-    firebase_rest_lib
-    firebase_rest_mocks
-    firebase_testing
-)
+if (MSVC OR APPLE)
+  firebase_cpp_cc_test(
+    firebase_auth_user_desktop_test
+    SOURCES
+      desktop/user_desktop_test.cc
+    DEPENDS
+      firebase_app_for_testing
+      firebase_auth
+      firebase_auth_desktop_test_util
+      firebase_rest_lib
+      firebase_rest_mocks
+      firebase_testing
+  )
+endif()
 
 firebase_cpp_cc_test(
   firebase_auth_request_heartbeat_test