Bump cypress from 5.3.0 to 5.4.0 in /packages/webapp

Bumps [cypress](https://github.com/cypress-io/cypress) from 5.3.0 to 5.4.0.
- [Release notes](https://github.com/cypress-io/cypress/releases)
- [Changelog](https://github.com/cypress-io/cypress/blob/develop/.releaserc.base.js)
- [Commits](https://github.com/cypress-io/cypress/compare/v5.3.0...v5.4.0)

Signed-off-by: dependabot[bot] <support@github.com>

packages/webapp/package.json

@@ -36,7 +36,7 @@
     "skynet-js": "2.0.9"
   },
   "devDependencies": {
-    "cypress": "5.3.0",
+    "cypress": "5.4.0",
     "cypress-file-upload": "4.1.1",
     "eslint": "7.11.0",
     "eslint-config-prettier": "6.12.0",