feat: Model Competitions - Model Contributors

[roselynh100]

Changelogs

• Added contributors field to Model class, so users can specify a list of contributors on model upload

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Checklist:

• Was this PR discussed in an issue? It is recommended to first discuss a new feature into a GitHub issue before opening a PR.
• Add tests to cover the fixed bug(s) or the newly introduced feature(s) (if appropriate).
• Update the API documentation if a new function is added, or an existing one is deleted.
• Write concise and explanatory changelogs above.
• If possible, assign one of the following labels to the PR: feature, fix, chore, documentation or test (or ask a maintainer to do it for you).

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discussion related to that PR

[Andrewq11]

Short and sweet. Great work, @roselynh100!