fix: Commit search endpoint uses wrong type for deserialization

[halfdanthemild]

In models::repo::Commit, author - which is of type CommitAuthor (https://github.com/XAMPPRocky/octocrab/blob/main/src/models/repos.rs#L160) - has a non-optional name field. But this was causing crashes for me with the error Serde error: missing field 'name' as Github does not return the author name here. name is also not present in the example response in the Github docs for this endpoint either (https://docs.github.com/en/rest/search/search?apiVersion=2022-11-28#search-commits):

"author": {
  "login": "octocat",
  "id": 583231,
  "node_id": "MDQ6VXNlcjU4MzIzMQ==",
  "avatar_url": "https://avatars.githubusercontent.com/u/583231?v=3",
  "gravatar_id": "",
  "url": "https://api.github.com/users/octocat",
  "html_url": "https://github.com/octocat",
  "followers_url": "https://api.github.com/users/octocat/followers",
  "following_url": "https://api.github.com/users/octocat/following{/other_user}",
  "gists_url": "https://api.github.com/users/octocat/gists{/gist_id}",
  "starred_url": "https://api.github.com/users/octocat/starred{/owner}{/repo}",
  "subscriptions_url": "https://api.github.com/users/octocat/subscriptions",
  "organizations_url": "https://api.github.com/users/octocat/orgs",
  "repos_url": "https://api.github.com/users/octocat/repos",
  "events_url": "https://api.github.com/users/octocat/events{/privacy}",
  "received_events_url": "https://api.github.com/users/octocat/received_events",
  "type": "User",
  "site_admin": false
}

Using models::commits::Commit instead seems to work.