Fix test workflow

[spilth]

Problem

• The mysql2 gem is incompatible with the latest MySQL client provided by Homebrew on macOS, preventing bundle install from completing successfully
• A number of gems have vulnerabilities at the current versions which cause the bundle-audit check task to fail the build
• The current checkout action is deprecated and needs to be upgraded

Solution

• Upgrade the mysql2 gem version.
• Upgrade the gem versions of vulnerable gems.
  • Note that view_component is now pinned to a 2.X version to avoid upgrading to 3.x (which likely requires some research/testing).
• Upgrade the version of actions/checkout being used.

Type

Dependencies

[mnyrop]

LGTM and can confirm that everything works locally with the upgraded gems 👍🏻