build: update to node 22 and pnpm (#3616)

This commit brings the project to support node 22 which became LTS and
fixes broken builds with typescript 5.7+ until vue-tsc is updated and
replaces npm with pnpm.

- Update tsconfig for node 22
- Pin typescript to 5.6.x to not break vue-tsc
- Replace npm with pnpm (corepack recommended)
- Update Makefile and main workflow for pnpm
- Migrate to eslint 9 flat config
- Fix broken imports
- Exclude non-TS vue files for vue-tsc

frontend/src/utils/auth.ts

@@ -1,6 +1,7 @@
 import { useAuthStore } from "@/stores/auth";
 import router from "@/router";
-import { JwtPayload, jwtDecode } from "jwt-decode";
+import type { JwtPayload } from "jwt-decode";
+import { jwtDecode } from "jwt-decode";
 import { baseURL, noAuth } from "./constants";
 import { StatusError } from "@/api/utils";