[RUN AS-IF-FOSS] Run autocorrection for RSpec/TimecopFreeze in spec

What does this MR do?

In !39656 (merged), we added a cop to detect usages of Timecop.freeze and suggest using freeze_time instead. Before this cop can be enabled, we need to fix existing offences in the codebase.

This MR is the result of running autocorrection for this cop in the spec directory. Two types of calls to Timecop.freeze are replaced with freeze_time:

• Timecop.freeze with no arguments and a block
• Timecop.freeze with Time.now and a block

freeze_time does not take the time as an argument, and defaults to Time.now. Any calls to Timecop.freeze with an argument will need to be replaced with travel_to.

Related to #214432 (closed)

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation (if required)
• Code review guidelines
• [-] Merge request performance guidelines
• [-] Style guides
• [-] Database guides
• [-] Separation of EE specific content

Availability and Testing

• [-] Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers
• [-] Informed Infrastructure department of a default or new setting change, if applicable per definition of done

Security

If this MR contains changes to processing or storing of credentials or tokens, authorization and authentication methods and other items described in the security review guidelines:

• [-] Label as security and @ mention @gitlab-com/gl-security/appsec
• [-] The MR includes necessary changes to maintain consistency between UI, API, email, or other methods
• [-] Security reports checked/validated by a reviewer from the AppSec team