Unblock subsequent Singleton.createInstance() (#3225)

- Also fix clusters with unknown workspaces

Signed-off-by: Sebastian Malton <sebastian@malton.name>

src/migrations/hotbar-store/5.0.0-beta.10.ts

@@ -75,6 +75,11 @@ export default {
         for (const workspaceId of cluster.workspaces ?? [cluster.workspace].filter(Boolean)) {
           const workspaceHotbar = workspaceHotbars.get(workspaceId);
 
+          if (!workspaceHotbar) {
+            migrationLog(`Cluster ${uid} has unknown workspace ID, skipping`);
+            continue;
+          }
+
           migrationLog(`Adding cluster ${uid} to ${workspaceHotbar.name}`);
 
           if (workspaceHotbar?.items.length < defaultHotbarCells) {