… read_my_cnf_files

Description

Only read "my" configuration files once, rather than once per call to read_my_cnf_files

read_my_cnf_files used to call read_config_files every time. Now, read_config_files is called once with parameter self.cnf_files. This way, it is avoided to re-read the same file(s) several times from the file system

Checklist

• I've added this contribution to the changelog.md.
• I've added my name to the AUTHORS file (or it's already there).
• I ran uv run ruff check && uv run ruff format to lint and format the code.