MNT: Replace master with main

[pllim]

This PR attempts to replace all mention of master to main in this repository. This should be reviewed and merged right after the maintainer has renamed the default branch.

This is an automated update made by the batchpr tool 🤖 - feel free to close if it doesn't look good! You can report issues to @pllim.

This is part of #252

[pllim]

Does depend on ci-helpers renaming.

[codecov]

Codecov Report

Merging #253 (8091abb) into master (f72aa90) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master     #253   +/-   ##
=======================================
  Coverage   75.51%   75.51%           
=======================================
  Files          44       44           
  Lines        5129     5129           
=======================================
  Hits         3873     3873           
  Misses       1256     1256           

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[bsipocz]

I've rebased this, and it should be ready to go now -- merging should coincide with changing the settings on the repo though.

[tomdonaldson]

This looks good. Thanks for doing this!

[bsipocz]

Thanks @pllim

And now I go ahead and update the repo settings. Long term we should think about having the "pyvo maintainers" group have admin access to have the ability to edit the repo settings and do the release without interactions from the devops team. Opting in to more branch protection would provide enough safeguard against accidental pushes to the main branch, etc.