try node 20 for ci (#2275)

* try node 20 for ci

* lint

Author: joelhawksley

.github/workflows/ci.yml

@@ -118,7 +118,7 @@ jobs:
         working-directory: 'view_component'
     - uses: actions/setup-node@v4
       with:
-        node-version: 16
+        node-version: 20
         cache: 'npm'
         cache-dependency-path: 'primer_view_components/package-lock.json'
     - name: Build and test with Rake

lib/view_component/slotable.rb

@@ -431,7 +431,7 @@ def set_slot(slot_name, slot_definition = nil, *args, &block)
     def set_polymorphic_slot(slot_name, poly_type = nil, *args, &block)
       slot_definition = self.class.registered_slots[slot_name]
 
-      if !slot_definition[:collection] && (defined?(@__vc_set_slots) && @__vc_set_slots[slot_name])
+      if !slot_definition[:collection] && defined?(@__vc_set_slots) && @__vc_set_slots[slot_name]
         raise ContentAlreadySetForPolymorphicSlotError.new(slot_name)
       end