smarthttp: Skip flaky test in testServerPostUploadPackGitConfigOptions
requested to merge 5027-flaky-test-testserver_postuploadpacksidechannel_gitconfigoptions-no_config_options into master
The test TestServer_PostUploadPackSidechannel_gitConfigOptions/no_config_options/failing_request_because_of_hidden_ref_config is flaky in nature. Let's skip it till we can find a fix for the race condition.
Part of #5027 (closed)