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/components/files/ExtendedImage.vue

@@ -14,15 +14,15 @@
   </div>
 </template>
 <script setup lang="ts">
-import throttle from "lodash/throttle";
+import { throttle } from "lodash-es";
 import UTIF from "utif";
 import { onBeforeUnmount, onMounted, ref, watch } from "vue";
 
 interface IProps {
   src: string;
-  moveDisabledTime: number;
-  classList: any[];
-  zoomStep: number;
+  moveDisabledTime?: number;
+  classList?: any[];
+  zoomStep?: number;
 }
 
 const props = withDefaults(defineProps<IProps>(), {