chore: Make theme-pack plugin a public package (#1250)

- Wasn't being published because it was configured as a private package

Author: mofojed

plugins/theme-pack/src/js/package.json

@@ -13,5 +13,7 @@
   "devDependencies": {
     "@deephaven/plugin": "^1.6.0"
   },
-  "private": true
+  "publishConfig": {
+    "access": "public"
+  }
 }