Rename "master" branch to "main"

[gclough]

The current practice is to use main for the main branch, instead of master... so we should swap, to keep up-to-date:

https://www.linkedin.com/pulse/technology-notes-how-tos-infrastructure-git-master-main-eldritch/

[natedennis]

or you could leave it alone and be stable instead of trendy

[otakup0pe]

Strongly agree with renaming the main branch to something other than master. Only concern is whether this will interfere with how galaxy works.

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[otakup0pe]

Going to point out that these days GitHub defaults to main. What would be needed to make this change, other than updating CI flows?

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This issue has been marked 'stale' due to lack of recent activity. If there is no further activity, the issue will be closed in another 30 days. Thank you for your contribution!