The spec is checking that when no report file exists, the report is {}.
The problem is that by default we're looking for ENV['SUITE_FLAKY_RSPEC_REPORT_PATH'].
In !14681 (merged), the spec passed because the content of the file at the path ENV['SUITE_FLAKY_RSPEC_REPORT_PATH'] was {} since no actual report had been populated (since the report name has been changed and it's only populated on master).
Once merged, and flaky tests were detected and saved into the report at ENV['SUITE_FLAKY_RSPEC_REPORT_PATH'], the spec was silently loading this default file, and the test would fail since the file was not equal to {} anymore.
Stubbing ENV['SUITE_FLAKY_RSPEC_REPORT_PATH'] solves the issue.