chore: upgrade to eslint 9 (#2348)

* root + server

* frontend

* frontend-2

* dui3

* dui3

* tailwind theme

* ui-components

* preview service

* viewer

* viewer-sandbox

* fileimport-service

* webhook service

* objectloader

* shared

* ui-components-nuxt

* WIP full config

* WIP full linter

* eslint projectwide util

* minor fix

* removing redundant ci

* clean up test errors

* fixed prettier formatting

* CI improvements

* TSC lint fix

* 'buildBatch' needs to be async since some batch types (like Text) require it. Removed a disabled liniting rule from ObjLoader

* removed unnecessary void

---------

Co-authored-by: AlexandruPopovici <alexandrupopoviciioan@gmail.com>

workspace.code-workspace

@@ -113,7 +113,8 @@
     },
     "vue.complete.casing.props": "kebab",
     "vue.inlayHints.missingProps": true,
-    "circleci.persistedProjectSelection": ["gh/specklesystems/speckle-server"]
+    "circleci.persistedProjectSelection": ["gh/specklesystems/speckle-server"],
+    "eslint.experimental.useFlatConfig": true
   },
   "extensions": {
     // See https://go.microsoft.com/fwlink/?LinkId=827846 to learn about workspace recommendations.