Fix twenty-front performances (#6744)

I have investigated the performance of our frontend vite build:
`npx nx run twenty:start` of `npx nx run twenty:build`

RAM usage:
- 160Mb: vite serve
- background typescript checker: 2.5GB
- background eslint checker: 3.5GB

I'm introducing two environment variables in FE .env to disable these
checkers on lower configuration (and to disable them from CD build):
```
# VITE_DISABLE_TYPESCRIPT_CHECKER=true
# VITE_DISABLE_ESLINT_CHECKER=true
```

packages/twenty-front/.env.example

@@ -3,3 +3,5 @@ GENERATE_SOURCEMAP=false
 
 # ———————— Optional ————————
 # CHROMATIC_PROJECT_TOKEN=
+# VITE_DISABLE_TYPESCRIPT_CHECKER=true
+# VITE_DISABLE_ESLINT_CHECKER=true