Update dependency @actions/github to v5

This PR contains the following updates:

Package	Change	Age	Adoption	Passing	Confidence
@actions/github (source)	`4.0.0` -> `5.1.1`

Release Notes

actions/toolkit

### [`v5.1.1`](https://togithub.com/actions/toolkit/blob/HEAD/packages/github/RELEASES.md#511) - Export default octokit options [#1188](https://togithub.com/actions/toolkit/pull/1188) ### [`v5.1.0`](https://togithub.com/actions/toolkit/blob/HEAD/packages/github/RELEASES.md#510) - Add additionalPlugins parameter to getOctokit method [#1181](https://togithub.com/actions/toolkit/pull/1181) - Dependency updates [#1180](https://togithub.com/actions/toolkit/pull/1180) ### [`v5.0.3`](https://togithub.com/actions/toolkit/blob/HEAD/packages/github/RELEASES.md#503) - - Update to v2.0.1 of `@actions/http-client` [#1087](https://togithub.com/actions/toolkit/pull/1087) ### [`v5.0.2`](https://togithub.com/actions/toolkit/blob/HEAD/packages/github/RELEASES.md#502) - Update to v2.0.0 of `@actions/http-client` ### [`v5.0.1`](https://togithub.com/actions/toolkit/blob/HEAD/packages/github/RELEASES.md#501) - [Update Octokit Dependencies](https://togithub.com/actions/toolkit/pull/1037) ### [`v5.0.0`](https://togithub.com/actions/toolkit/blob/HEAD/packages/github/RELEASES.md#500) - [Update @actions/github to include latest octokit definitions](https://togithub.com/actions/toolkit/pull/783) - [Add urls to context](https://togithub.com/actions/toolkit/pull/794)