Directly import from index.ts in pdf split code

This avoids an import error for me locally, so it may help other users.

Author: awalker4

src/hooks/custom/SplitPdfHook.ts

@@ -22,7 +22,7 @@ import {
   prepareResponseHeaders,
   splitPdf,
   stringToBoolean,
-} from "./utils";
+} from "./utils/index";
 import {
   MIN_PAGES_PER_THREAD,
   PARTITION_FORM_FILES_KEY,

test/unit/utils/pdf.test.ts

@@ -6,7 +6,7 @@ import {
   pdfPagesToBlob,
   splitPdf,
 } from "../../../src/hooks/custom/utils";
-import { getOptimalSplitSize } from "../../../hooks/custom/utils";
+import { getOptimalSplitSize } from "../../../hooks/custom/utils/index";
 import { MAX_PAGES_PER_THREAD, MIN_PAGES_PER_THREAD } from "../../../hooks/custom/common";
 
 describe("Pdf utility functions", () => {