Implement SwiftLint in Continuous Integration - Discussion

[mildm8nnered]

Opening this as a place to hang discussion.

Makefile entry should be easy enough, perhaps

swiftlint:
        swiftlint --quiet

but SwiftLint will exit with 0 on any successful run, whether violations are detected or not, so possibly we'll want a wrapper script with an exit value

There's also the question of how SwiftLint should be installed/assumptions about paths on the CI machines. For example, homebrew installs SwiftLint at /opt/homebrew/bin/swiftlint, which may (or may not) be on the CI user's path.

See for example, https://github.com/realm/SwiftLint#installation

[ileitch]

Implemented in #806 using mise.