Git - Dependabot Pull Request

In Github, see Pull Requests, select an open request,  Files changed. Observe just the gemfile.lock has changed. e.g.
Bump rack from 2.2.7 to 2.2.20

 -  rack (2.2.7)
 +  rack (2.2.20)

 Merging this Pull Request is broadly equivalent to running locally:

 $bundle update rack

 Bundler when run, finds there is an updated version of the gem that meets the gemfile's stipulated flexibility requirements, so installs it and updates the gemfile.lock accordingly.

Having merged a PR, run locally

$git pull origin main
$bundle

This brings local and remote repo in line.