Jwt: implement clear route cache (#30699)

Commit Message: Follow-up to #30356 to implement clear_route_cache.
Risk Level: low, new field
Testing: done
Docs Changes: none
Release Notes: none
Issue: #29681

Mirrored from https://github.com/envoyproxy/envoy @ f0248a4765b483a2c103a814483eff79a2c1e4ed

envoy/extensions/filters/http/jwt_authn/v3/config.proto

@@ -320,7 +320,6 @@ message JwtProvider {
   // This header is only reserved for jwt claim; any other value will be overwritten.
   repeated JwtClaimToHeader claim_to_headers = 15;
 
-  // [#not-implemented-hide:]
   // Clears route cache in order to allow JWT token to correctly affect
   // routing decisions. Filter clears all cached routes when:
   //