Ruby3: Fix escaped HTML tags on SSH key profile view

What does this MR do and why?

Fixes a typebug in Ruby 3 only. This is not broken in Ruby2!

See #374074 (closed) and https://gitlab.com/gitlab-org/gitlab/-/jobs/3036004478.

Screenshots or screen recordings

Before	After

How to set up and validate locally

asdf local ruby 3.0.4
bin/rspec ./spec/views/profiles/keys/_key.html.haml_spec.rb

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