Upgrade to github.com/golang-jwt/jwt/v5 and use github.com/MicahParks/keyfunc/v2 for JWK Set client

[MicahParks]

The purpose of this pull request is to upgrade the upstream JWT package to github.com/golang-jwt/jwt/v5 and replace the built-in JWK Set client with github.com/MicahParks/keyfunc/v2.

Both of these are breaking changes. I would prefer to target a v4-candidate or similar branch. There is an opportunity to make other breaking changes. I'm not sure if the maintainers have other breaking changes in mind.

Intended to close #128

[ReneWerner87]

thank you , will look at it (latest by the weekend), had overlooked it

[gaby]

@MicahParks seems like https://github.com/golang-jwt/jwt/releases does that mean the import changes to v5?

[ReneWerner87]

are we good with the current changes ? is there anything left open ?

[MicahParks]

are we good with the current changes ? is there anything left open ?

There are a few threads open tied to TODO comments in the code that I made. Changes for these TODOs is optional, but I'd like to remove the TODOs before the pull request is merged.

1. There is this thread about a cosmetic rename.
2. There is this thread about a user specified JWT signature algorithm for verification.
3. There is this thread about error vs panic.

[efectn]

are we good with the current changes ? is there anything left open ?

There are a few threads open tied to TODO comments in the code that I made. Changes for these TODOs is optional, but I'd like to remove the TODOs before the pull request is merged.

1. There is this thread about a cosmetic rename.
2. There is this thread about a user specified JWT signature algorithm for verification.
3. There is this thread about error vs panic.

Made some comments about TODOs