Fix OpenBao OIDC token exchange compatibility

src/internal/server/oidc/token.go

@@ -111,6 +111,9 @@ func (h *TokenHandler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
 		"exp": exp.Unix(),
 		"iat": now.Unix(),
 	}
+	if sess.Nonce != "" {
+		claims["nonce"] = sess.Nonce
+	}
 
 	scopeSet := make(map[string]bool)
 	for _, s := range sess.Scopes {