Fix gitlab_com rake task that checks for the latest tag

Adding ~"Pick into 11.6" because this is blocking automatic deploys to staging.

Build::Info.latest_tag ends with a carriage return.

Before:

[1] pry(main)> Build::Check.match_tag?(Build::Info.latest_tag)
fatal: No names found, cannot describe anything.
=> false

After:

[2] pry(main)> Build::Check.match_tag?(Build::Info.latest_tag.chomp)
11.6.0+rc7.ee.0
=> true