Update dependency @cypress/webpack-preprocessor to v5.15.7

Author: renovate[bot]

package-lock.json

@@ -4,7 +4,7 @@
     "url": "https://github.com/e2e-boilerplate/cypress-typescript-webpack-chai-assert/issues"
   },
   "dependencies": {
-    "@cypress/webpack-preprocessor": "5.15.6",
+    "@cypress/webpack-preprocessor": "5.15.7",
     "cypress": "5.6.0",
     "rimraf": "3.0.2",
     "ts-loader": "9.4.2",