Fix missing webpack test dep

Author: timfish

packages/integration-tests-next/fixtures/webpack5/build-info.test.ts

@@ -5,7 +5,7 @@ test(import.meta.url, ({ runBundler, readOutputFiles }) => {
   runBundler();
   expect(readOutputFiles()).toMatchInlineSnapshot(`
     {
-      "basic.js": "!function(){try{var e="undefined"!=typeof window?window:"undefined"!=typeof global?global:"undefined"!=typeof globalThis?globalThis:"undefined"!=typeof self?self:{};e.SENTRY_RELEASE={id:"build-information-injection-test"};e.SENTRY_BUILD_INFO={"deps":["@babel/preset-react","@sentry/webpack-plugin","webpack","webpack-cli"],"depsVersions":{"webpack":5},"nodeVersion":"NODE_VERSION"};var n=(new e.Error).stack;n&&(e._sentryDebugIds=e._sentryDebugIds||{},e._sentryDebugIds[n]="00000000-0000-0000-0000-000000000000",e._sentryDebugIdIdentifier="sentry-dbid-00000000-0000-0000-0000-000000000000");}catch(e){}}();
+      "basic.js": "!function(){try{var e="undefined"!=typeof window?window:"undefined"!=typeof global?global:"undefined"!=typeof globalThis?globalThis:"undefined"!=typeof self?self:{};e.SENTRY_RELEASE={id:"build-information-injection-test"};e.SENTRY_BUILD_INFO={"deps":["@babel/preset-react","@sentry/webpack-plugin","babel-loader","webpack","webpack-cli"],"depsVersions":{"webpack":5},"nodeVersion":"NODE_VERSION"};var n=(new e.Error).stack;n&&(e._sentryDebugIds=e._sentryDebugIds||{},e._sentryDebugIds[n]="00000000-0000-0000-0000-000000000000",e._sentryDebugIdIdentifier="sentry-dbid-00000000-0000-0000-0000-000000000000");}catch(e){}}();
     /******/ (() => { // webpackBootstrap
     /******/ 	"use strict";
     // eslint-disable-next-line no-console

packages/integration-tests-next/fixtures/webpack5/package.json

@@ -4,6 +4,7 @@
   "private": true,
   "type": "module",
   "dependencies": {
+    "babel-loader": "^8.0.0",
     "webpack": "5.105.4",
     "webpack-cli": "6.0.1",
     "@babel/preset-react": "7.23.3",