fix: do not mutate and return the initial options

[darkgl0w]

Hello.

This PR aims to :

• upgrade package dependencies
• avoid initial options mutation and return the original options to the user through the fastify.jwt.options decorator property (fix initial options mutation #213)

Checklist

• run npm run test and npm run benchmark
• tests and/or benchmarks are included
• documentation is changed or added
• commit message and code follows the Developer's Certification of Origin
  and the Code of conduct

[mcollina]

lgtm

[stale]

This issue has been automatically marked as stale because it has not had recent activity. It will be closed if no further activity occurs. Thank you for your contributions.