Rebuild dist files.

dist/js/splide.cjs.js

@@ -2448,7 +2448,7 @@ const Slide = (Splide, Components, options, event) => {
 class Splide {
   static defaults = {};
   static STATES = STATES;
-  static Extensions;
+  static Extensions = {};
   root;
   event = EventInterface();
   Components = {};

dist/js/splide.esm.js

@@ -2444,7 +2444,7 @@ const Slide = (Splide, Components, options, event) => {
 class Splide {
   static defaults = {};
   static STATES = STATES;
-  static Extensions;
+  static Extensions = {};
   root;
   event = EventInterface();
   Components = {};

dist/js/splide.js

@@ -2444,7 +2444,7 @@
   class Splide {
     static defaults = {};
     static STATES = STATES;
-    static Extensions;
+    static Extensions = {};
     root;
     event = EventInterface();
     Components = {};

src/js/core/Splide/Splide.ts

@@ -43,7 +43,7 @@ export class Splide {
   /**
    * Stores extension constructors.
    */
-  static readonly Extensions: Record<string, ComponentConstructor>;
+  static readonly Extensions: Record<string, ComponentConstructor> = {};
 
   /**
    * The root element where the Splide is applied.