fix: do not create hash in frontend (#6788)

blob is already hashed in https://github.com/toeverything/AFFiNE/blob/6fdf45d4d064ebac9691a71abc800a90c5e6bfb9/packages/backend/server/src/plugins/copilot/resolver.ts#L294

packages/frontend/core/src/components/blocksuite/block-suite-editor/ai/request.ts

@@ -8,16 +8,6 @@ const TIMEOUT = 50000;
 
 const client = new CopilotClient();
 
-async function calculateBlobHash(blob: Blob) {
-  const buffer = await blob.arrayBuffer();
-  const hashBuffer = await crypto.subtle.digest('SHA-256', buffer);
-  const hashArray = Array.from(new Uint8Array(hashBuffer));
-  return hashArray
-    .map(byte => byte.toString(16).padStart(2, '0'))
-    .join('')
-    .slice(0, 32);
-}
-
 export type TextToTextOptions = {
   docId: string;
   workspaceId: string;
@@ -86,7 +76,7 @@ async function createSessionMessage({
         if (blob instanceof File) {
           return blob;
         } else {
-          return new File([blob], await calculateBlobHash(blob), {
+          return new File([blob], sessionId, {
             type: blob.type,
           });
         }