Update dependency jwt to v3 (#108)

The notable breaking changes:
- The `JWT::EncodedToken#payload` method will raise an error if accessed before
  the token signature has been verified.
- JWKs produced by older versions of the gem are not compatible.

Co-authored-by: renovate[bot] <29139614+renovate[bot]@users.noreply.github.com>

Author: renovate[bot]

template/{{app_name}}/Gemfile.lock

@@ -212,7 +212,7 @@ GEM
       activesupport (>= 5.0.0)
     jmespath (1.6.2)
     json (2.11.3)
-    jwt (2.10.1)
+    jwt (3.1.2)
       base64
     language_server-protocol (3.17.0.4)
     launchy (3.1.0)