update coarse-graining-workshop version to 2026-04-21

Author: jimboid

assets.json

@@ -148,7 +148,7 @@
       "longdesc": ""
     },
     "coarse-graining-workshop": {
-      "latest": "2026-04-20",
+      "latest": "2026-04-21",
       "name": "Introducing Coarse-Graining",
       "category": "advanced",
       "shortdesc": "This workshop introduces tools for setup and running coarse-grain simulations.",