Add support for multiple OpenID providers with role policies (#14223)

- When using multiple providers, claim-based providers are not allowed. All
providers must use role policies.

- Update markdown config to allow `details` HTML element

cmd/config-migrate.go

@@ -2649,7 +2649,6 @@ func migrateV30ToV31MinioSys(objAPI ObjectLayer) error {
 
 	cfg.Version = "31"
 	cfg.OpenID = openid.Config{}
-	cfg.OpenID.JWKS.URL = &xnet.URL{}
 
 	cfg.Policy.OPA = opa.Args{
 		URL:       &xnet.URL{},