Bump go-github to v49.0.0

[AnitaErnszt]

Resolves #1262

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Behavior

Other information

• v49 includes 2 breaking changes:
  • Fix JSON protection unmarshal error (Fix JSON protection unmarshal error google/go-github#2606)
  • Change actions billing structs to maps (Change actions billing structs to maps google/go-github#2597)

I have checked, and it seems these breaking changes don't affect the terraform-provider-github, but please double check, I'm still very new to go.

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Additional info

Pull request checklist

• Tests for the changes have been added (for bug fixes / features)
• Docs have been reviewed and added / updated if needed (for bug fixes / features)
• Added the appropriate label for the given change

Does this introduce a breaking change?

Please see our docs on breaking changes to help!

• Yes (Please add the Type: Breaking change label)
• No

If Yes, what's the impact:

• N/A

Pull request type

Please add the corresponding label for change this PR introduces:

• Bugfix: Type: Bug
• Feature/model/API additions: Type: Feature
• Updates to docs or samples: Type: Documentation
• Dependencies/code cleanup: Type: Maintenance

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[AnitaErnszt]

@kfcampbell please kindly check if I missed anything

[kfcampbell]

Looks good to me!