If you keep your CI scripts as shell scripts and put them into a runnable file included in your project you can run your CI scripts locally so you can test the work flow on your machine. It's also handy in case CI is down you can still test and deploy your code. Lastly it lets you easily jump between CI providers since a majority of your logic is in a generic shell script.
For example in my CI specific files I typically only call `./run ci:install-deps && ./run ci:test`. Then there's a tiny bit of boiler plate in each CI provider's yml file to handle specific things for that provider.
If your app is running in Docker most of the heavy duty dependencies are all contained there. The dependencies I install directly in CI end up being things like installing shellcheck and helper scripts for CI (like tiny scripts that let you wait until a process is ready). Having WSL 2 is nice here because these are very small tools that I want locally installed anyways but even if you use macOS you could install these dependencies using brew instead.
A working example of this is here: https://github.com/nickjj/docker-flask-example
Check out the run script in the root of the project for "ci:" functions and the GH Actions yml file. This same strategy applies to GitLab or any other CI provider too.