Removed the unused date-fns dependency from shade (#28330)

ref https://linear.app/ghost/issue/PLA-60

`apps/shade` declared `date-fns@4.1.0` as a direct dependency but
**never imports it** — there's no `date-fns` reference anywhere in the
package's source. The calendar component pulls in
`react-day-picker@9.14.0`, which depends on date-fns 4.x itself, so
shade's direct declaration was redundant.

Author: 9larsons

apps/shade/package.json

@@ -140,7 +140,6 @@
         "clsx": "catalog:",
         "cmdk": "1.1.1",
         "color": "5.0.3",
-        "date-fns": "4.1.0",
         "lucide-react": "catalog:",
         "moment-timezone": "^0.5.48",
         "react": "catalog:",