react-scripts: ESLint blocking build after upgrade to v4

[EricKulchycki]

Hello!
I've recently been trying to undergo the process of upgrading react-scripts to version 4. My issue is that my team has recently implemented a proper eslint config within the last month (we were doing something wrong and basically only prettier was formatting our code), so now we have many linter errors within our project. Previously the errors would not show up in the dev server or build unless they appeared in files we've recently modified (on a given branch).

Basically my question is if it is possible for me upgrade, but revert the behaviour of the build to only error on files we've recently modified? Basically I'm trying to avoid having to go through and unnecessarily modify every file that hasn't been touched in the last month if I don't need to.

EDIT: Very sorry I did not see this discussion. If anyone has any suggestions in the meantime though much appreciated. #10344