fix: Import of runtime

Author: asafgardin

src/factory.ts

@@ -2,7 +2,7 @@ import { BrowserFilesHandler } from './files/BrowserFilesHandler';
 import { BrowserFetch, Fetch, NodeFetch } from './fetch';
 import { NodeFilesHandler } from './files/NodeFilesHandler';
 import { BaseFilesHandler } from './files/BaseFilesHandler';
-import { isBrowser, isWebWorker } from 'runtime';
+import { isBrowser, isWebWorker } from './runtime';
 
 export function createFetchInstance(): Fetch {
   if (isBrowser || isWebWorker) {

src/files/NodeFilesHandler.ts

@@ -1,7 +1,7 @@
 import { FilePathOrFileObject } from 'types';
 import { BaseFilesHandler } from './BaseFilesHandler';
 import { FormDataRequest } from 'types/API';
-import { isNode } from 'runtime';
+import { isNode } from '../runtime';
 
 export class NodeFilesHandler extends BaseFilesHandler {
   private async convertReadableStream(readableStream: ReadableStream): Promise<NodeJS.ReadableStream> {