default branch: master -> main

[okken]

Most projects I work with have already switched master to main.

[flub]

Thanks for prompting. I've done this now, but I lost two PRs along the way... any clue where to find them again?

[flub]

To keep track of this, the one I want back is still here it seems: https://github.com/pytest-dev/pytest-timeout/pull/154