ci: Attempt to fix restyled.io test (#6116)

We're now getting an error with exit code 127, so this commit adds the suggested solution of telling Restyled the exact command needed to run:

    https://github.com/restyled-io/restyled.io/wiki/Common-Errors:-Prettier#prettier-with-tailwindcss-executable-file-not-found-in-path

.restyled.yaml

@@ -57,6 +57,9 @@ restylers:
       - migrations/versions
   - name: prettier
     image: restyled/restyler-prettier:v1.19.1-2
+    command:
+      - prettier
+      - --write
     include:
       - client/app/**/*.js
       - client/app/**/*.jsx