Go GitHub update

[mattburgess]

This bumps the vendored go-github library up to v21.0.1 in order to address https://github.com/terraform-providers/terraform-provider-github/issues/185. If doesn't quite get us up to the latest version due to google/go-github#1114.

I've committed each version bump separately in order to ease any bisection that might be necessary. This passed a make build && make test run but I'm unable to perform any acceptance tests.

[radeksimko]

Hi @mattburgess
sorry it took us a while to get to your PR.

We have just recently migrated over to go modules which means this PR would need to be reworked quite significantly.

Additionally I think we should phase out the webhook name in a separate PR and address this in the schema too. I will raise a PR for that first.

[radeksimko]

Also I just found this thread: google/go-github#1117

I'm not sure whether we want to phase out the field then. I will try to contact GitHub then.

[mattburgess]

@radeksimko thanks for the feedback. I saw that PR before I started this one, but thought I'd raise it anyway based on not knowing when either might get merged. So, I'm happy for this one to be closed. I can try to help out by raising another version bump based on the new go modules way of doing things, or if you think it's trivial enough that me doing that just creates more work on your side then I'm happy to let it slide.

As it is, GitHub Enterprise 2.16.2 fixes the regression (https://enterprise.github.com/releases/2.16.2/notes) so selfishly I'm now no longer affected by the particular issue that drove this PR in the first place. More than happy to help out though if you think it'd be useful.

[bramwelt]

I just saw this PR and realized I was duplicating work in #203; Sorry! Happy to work on merging these two approaches (bump individual versions definitely helps for reviewing 👍 )

Hoping to get this updated so I can begin work on #87 . @radeksimko Any guidance would be appreciated.

[joestump]

@bramwelt @radeksimko also interested in getting #87 across the finish line. Let me know if I can do anything to help out.

[paultyng]

2.0.0 has been released, including SDK v25.0.2