opam-repo-ci

Work around UTF8 string length calculation differences

Update to FreeBSD 14.3

Make opam_repo_dir optional arg to lint_packages Allow linting an opam file without the need for it to be present inside an opam repository. The checks which need an opam repository are skipped.

Print lint errors grouped by package by default When running `opam-ci-check lint`, the output is now grouped by package names by default to make it easier to read for humans. The machine readable output used in CI can be obtained by passing an additional `--machine-readable` flag.

Add doc strings for Lint_error's error type

fix docs and tests

fix docs and tests