fix: correct fastify version on plugin genration

[gafreax]

This PR aims to fix the error that occurs when using the generate-plugin command, which copies the template with version ^4.0 instead of ^5.0.0
I've already opened an issue: #803

Checklist

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

[Eomm]

Thanks for the PR!

Could you add a test to compare the repo's package.json > fastify with the one in the template?
I'm sure we will miss it in the next major release if we don't add a test now 😔

[gafreax]

Yes for sure, I will provide it as soon as possible. I am already working on it

[gafreax]

Thank you, @Eomm, as soon as possible, I will provide the code with your suggestion. I'll try within today

[mcollina]

lgtm