chore: add missing licencse headers - #144

Platforms affected

Motivation and Context

• PR chore(workflows): update workflows, add ci.yml and release-audit.yml #143 complained about missing license headers on .gitattributes, .gitignore, .npmignore, .npmrc after adding release-audit.yml

Description

Testing

Checklist

• I've run the tests to see all new and existing tests pass
• I added automated test coverage as appropriate for this change
• Commit is prefixed with (platform) if this change only applies to one platform (e.g. (android))
• If this Pull Request resolves an issue, I linked to the issue in the text above (and used the correct keyword to close issues using keywords)
• I've updated the documentation if necessary