Bump @cypress/webpack-preprocessor from 5.15.5 to 5.15.6

Bumps [@cypress/webpack-preprocessor](https://github.com/cypress-io/cypress) from 5.15.5 to 5.15.6.
- [Release notes](https://github.com/cypress-io/cypress/releases)
- [Changelog](https://github.com/cypress-io/cypress/blob/develop/CHANGELOG.md)
- [Commits](https://github.com/cypress-io/cypress/compare/@cypress/webpack-preprocessor-v5.15.5...@cypress/webpack-preprocessor-v5.15.6)

---
updated-dependencies:
- dependency-name: "@cypress/webpack-preprocessor"
  dependency-type: direct:development
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

package-lock.json

@@ -79,7 +79,7 @@
 	"devDependencies": {
 		"@cypress/vue": "^2.2.4",
 		"@cypress/webpack-dev-server": "^1.8.4",
-		"@cypress/webpack-preprocessor": "5.15.5",
+		"@cypress/webpack-preprocessor": "5.15.6",
 		"@fontsource/roboto": "^4.5.8",
 		"@mdi/svg": "^7.0.96",
 		"@nextcloud/babel-config": "^1.0.0",