Revert "fix(core): add isServer to scrollspy controller"

This reverts commit 701f33f.

Author: bennypowers

core/pfe-core/controllers/scroll-spy-controller.ts

@@ -1,7 +1,5 @@
 import type { ReactiveController, ReactiveControllerHost } from 'lit';
 
-import { isServer } from 'lit';
-
 export interface ScrollSpyControllerOptions extends IntersectionObserverInit {
   /**
    * Tag names of legal link children.
@@ -35,15 +33,13 @@ export class ScrollSpyController implements ReactiveController {
   static #instances = new Set<ScrollSpyController>;
 
   static {
-    if (!isServer) {
-      addEventListener('scroll', () => {
-        if (Math.round(window.innerHeight + window.scrollY) >= document.body.scrollHeight) {
-          this.#instances.forEach(ssc => {
-            ssc.#setActive(ssc.#linkChildren.at(-1));
-          });
-        }
-      }, { passive: true });
-    }
+    addEventListener('scroll', () => {
+      if (Math.round(window.innerHeight + window.scrollY) >= document.body.scrollHeight) {
+        this.#instances.forEach(ssc => {
+          ssc.#setActive(ssc.#linkChildren.at(-1));
+        });
+      }
+    }, { passive: true });
   }
 
   #tagNames: string[];