@pquillere_zen Hello and welcome to the forum!
Thanks for alerting us to this, we will look into rolling our own SwiftLint image which can be updated much more frequently.
You can definitely install SwiftLint in macOS jobs with brew and run this directly. The reason we do not include this by default is the fact that SwiftLint is updated often and this would mean when we ship our images that the bundled SwiftLint would be outdated quite quickly - in turn this means extra job execution time spent updating homebrew, SwiftLint and any dependencies.
The example in the documentation demonstrates how you can run SwiftLint in parallel with an iOS build by employing a docker container (multi executor approach). The will save time and build credits.
We will update this thread when we have an alternative image ready.