Several years ago in #1245 capybara was pinned with this message:
Pin the capybara gem, until we can drop Ruby 2.2.0 Any capybara versions above 3.0.0 require a newer Ruby than 2.2.0, which we will support in line with Rails requirements.
Ruby 2.2 support has been dropped, so I think we can drop the pinning now?
It doesn't really do much at this point anyway since dependabot is automatically updating to the lastest versions soon after they are released.
Note: Merging this will probably generate some conflicts for #2118, or vice versa. If one of the PRs gets merged I'll update the other.