RSpec test order: Run spec/lib/gitlab/utils in random order

What does this MR do and why?

This MR enables spec/lib/gitlab/utils to be run in random order.

Contributes to #407877

Checked via:

scripts/rspec_check_order_dependence spec/lib/gitlab/utils_spec.rb spec/lib/gitlab/utils

This MR also fixes one order-dependent spec and enables two more utils spec to use fast_spec_helper.

How to set up and validate locally

bin/rspec --order random spec/lib/gitlab/utils_spec.rb spec/lib/gitlab/utils

MR acceptance checklist

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• I have evaluated the MR acceptance checklist for this MR.