Bump github.com/google/go-github

Currently the package `github` was [pinned](https://github.com/rajatjindal/krew-release-bot/blob/v0.0.44/go.mod#L7) to `v29.0.3` which was released back at [Feb 11, 2020](https://github.com/google/go-github/releases/tag/v29.0.3) - 3 years ago. - https://github.com/rajatjindal/krew-release-bot/blob/v0.0.44/go.mod#L7 - https://github.com/rajatjindal/krew-release-bot/blob/v0.0.44/pkg/releaser/git.go#L9 - https://github.com/rajatjindal/krew-release-bot/blob/v0.0.44/pkg/source/actions/webhook.go#L11 - https://github.com/rajatjindal/krew-release-bot/blob/v0.0.44/pkg/source/actions/action_runner.go#L13 - https://github.com/rajatjindal/krew-release-bot/blob/v0.0.44/vendor/modules.txt#L35-L38 - https://github.com/rajatjindal/krew-release-bot/tree/v0.0.44/vendor/github.com/google/go-github/v29 Maybe it could be bump to `v50+` for getting bug fixes, new features? - https://github.com/google/go-github/releases ```bash $ sed -i "" -e 's/v29 v29.0.3/v50 v50.2.0/g' go.mod $ sed -i "" -e 's/v29/v50/g' pkg/releaser/git.go $ sed -i "" -e 's/v29/v50/g' pkg/source/actions/webhook.go $ sed -i "" -e 's/v29/v50/g' pkg/source/actions/action_runner.go $ go mod vendor $ go mod tidy ```