Increase cmake test DISCOVERY_TIMEOUT from 5 to 120 seconds (#8403)

Summary:
cmake test discovery may timeout especially on Windows
platform. Increase it from default 5 seconds to 120 seconds.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/8403

Test Plan: Run Windows build 10 times without issue

Reviewed By: akankshamahajan15

Differential Revision: D29117455

Pulled By: jay-zhuang

fbshipit-source-id: 74f71833432f016776a59e070b0f4e146968f81b

CMakeLists.txt

@@ -1339,7 +1339,7 @@ if(WITH_TESTS)
       )
       target_link_libraries(${exename}${ARTIFACT_SUFFIX} testutillib${ARTIFACT_SUFFIX} testharness gtest ${THIRDPARTY_LIBS} ${ROCKSDB_LIB})
       if(NOT "${exename}" MATCHES "db_sanity_test")
-        gtest_discover_tests(${exename})
+        gtest_discover_tests(${exename} DISCOVERY_TIMEOUT 120)
         add_dependencies(check ${exename}${ARTIFACT_SUFFIX})
       endif()
       if("${exename}" MATCHES "env_librados_test")