Use YAML.safe_load_file for Bullet exclusions

`YAML.load_file` in Psych v4, which is used by Ruby 3.1, defaults to
`YAML.safe_load_file` (https://github.com/ruby/psych/issues/533). This
change in behavior breaks the loading of Bullet exclusions
(https://github.com/flyerhzm/bullet#configuration) in Ruby 3.1+ and
up. Fix this by using `YAML.safe_load_file` with `Range` as a
permitted class.

Relates to #396231

Changelog: changed