Fix flaky test in sessions_controller_test.rb

[jayjay-w]

Description

Testing devise's lock/unlock strategy is misbehaving in during CI runs.

References: CV2-4163

How has this been tested?

Ensured that rate limit checks are working

Things to pay attention to during code review

Please describe parts of the change that require extra attention during code review, for example:

Ensure that all rate limit tests are passing.

Checklist

• I have performed a self-review of my own code
• I have added unit and feature tests, if the PR implements a new feature or otherwise would benefit from additional testing
• I have added regression tests, if the PR fixes a bug
• I have added logging, exception reporting, and custom tracing with any additional information required for debugging
• I considered secure coding practices when writing this code. Any security concerns are noted above.
• I have commented my code in hard-to-understand areas, if any
• I have made needed changes to the README
• My changes generate no new warnings
• If I added a third party module, I included a rationale for doing so and followed our current guidelines

[codeclimate]

Code Climate has analyzed commit 2b3f9ab and detected 0 issues on this pull request.

The test coverage on the diff in this pull request is 100.0% (100% is the threshold).

This pull request will bring the total coverage in the repository to 100.0% (0.0% change).

View more on Code Climate.