Stop including isOffscreenCanvasSupported in the "StartRenderPage" message

With the previous commit this is now completely unused in API, hence it can be removed. This is done in a separate commit to make it easier to re-instate it, would the need ever arise.

src/core/document.js

@@ -417,8 +417,6 @@ class Page {
           this.resources,
           this.nonBlendModesSet
         ),
-        isOffscreenCanvasSupported:
-          this.evaluatorOptions.isOffscreenCanvasSupported,
         pageIndex: this.pageIndex,
         cacheKey,
       });

src/display/api.js

@@ -1521,25 +1521,19 @@ class PDFPageProxy {
       intentState.displayReadyCapability.promise,
       optionalContentConfigPromise,
     ])
-      .then(
-        ([
-          { transparency, isOffscreenCanvasSupported },
-          optionalContentConfig,
-        ]) => {
-          if (this.#pendingCleanup) {
-            complete();
-            return;
-          }
-          this._stats?.time("Rendering");
-
-          internalRenderTask.initializeGraphics({
-            transparency,
-            isOffscreenCanvasSupported,
-            optionalContentConfig,
-          });
-          internalRenderTask.operatorListChanged();
+      .then(([transparency, optionalContentConfig]) => {
+        if (this.#pendingCleanup) {
+          complete();
+          return;
         }
-      )
+        this._stats?.time("Rendering");
+
+        internalRenderTask.initializeGraphics({
+          transparency,
+          optionalContentConfig,
+        });
+        internalRenderTask.operatorListChanged();
+      })
       .catch(complete);
 
     return renderTask;
@@ -1763,7 +1757,7 @@ class PDFPageProxy {
   /**
    * @private
    */
-  _startRenderPage(transparency, isOffscreenCanvasSupported, cacheKey) {
+  _startRenderPage(transparency, cacheKey) {
     const intentState = this._intentStates.get(cacheKey);
     if (!intentState) {
       return; // Rendering was cancelled.
@@ -1772,10 +1766,7 @@ class PDFPageProxy {
 
     // TODO Refactor RenderPageRequest to separate rendering
     // and operator list logic
-    intentState.displayReadyCapability?.resolve({
-      transparency,
-      isOffscreenCanvasSupported,
-    });
+    intentState.displayReadyCapability?.resolve(transparency);
   }
 
   /**
@@ -2737,11 +2728,7 @@ class WorkerTransport {
       }
 
       const page = this.#pageCache.get(data.pageIndex);
-      page._startRenderPage(
-        data.transparency,
-        data.isOffscreenCanvasSupported,
-        data.cacheKey
-      );
+      page._startRenderPage(data.transparency, data.cacheKey);
     });
 
     messageHandler.on("commonobj", ([id, type, exportedData]) => {
@@ -3303,11 +3290,7 @@ class InternalRenderTask {
     });
   }
 
-  initializeGraphics({
-    transparency = false,
-    isOffscreenCanvasSupported = false,
-    optionalContentConfig,
-  }) {
+  initializeGraphics({ transparency = false, optionalContentConfig }) {
     if (this.cancelled) {
       return;
     }