Concurrent user work management using GIT in Katalon

We have integrated Katalon with GIT wherein we have Master and developing branch.

Simultaneously , there are two users who are working on same project.
So if user A has committed the changes and user B does a pull request , there is a conflict and unable to complete the pull request.
Attaching the screenshot for the same.

How can we user this concept using Katalon?

Now for the time being we are not adding .project and all the files related to settings while committing our codes to GitLab. In that way we are able to work parallelly.

Ideally we are expecting gitignore to handle this if we have included settings to be ignored. Not sure why gitignore concept is not working.