Change usage of deprecated property

[RSpeekenbrink]

Describe Pull request The UIEvent which property is deprecated. Use .key instead. https://developer.mozilla.org/en-US/docs/Web/API/UIEvent/which

If your PR is to fix an issue mention that issue here

Questions (please complete the following information):

• Have you personally loaded this code into an updated qbcore project and checked all it's functionality? yes
• Does your code fit the style guidelines? yes
• Does your PR fit the contribution guidelines? yes

[FBFezz]

Looks fine to me

[GhzGarage]

https://github.com/qbcore-framework/qb-radio/pull/41