Update the REXML dependency

[andrii-bodnar]

Dependabot couldn't update it automatically, so we need to update it manually. It is a transitive dependency.

Could not find compatible versions

Because simplecov-cobertura >= 2.0.0 depends on Ruby >= 2.5.0
  and Gemfile depends on simplecov-cobertura ~> 2.1,
  Ruby >= 2.5.0 is required.
So, because current Ruby version is = 2.4.10,
  version solving has failed.

https://github.com/crowdin/crowdin-api-client-ruby/actions/runs/11379872813/job/31658097998