chore(backend): bump webpack-cli in /services/backend

Bumps [webpack-cli](https://github.com/webpack/webpack-cli) from 6.0.1 to 7.0.1.
- [Release notes](https://github.com/webpack/webpack-cli/releases)
- [Changelog](https://github.com/webpack/webpack-cli/blob/main/CHANGELOG.md)
- [Commits](https://github.com/webpack/webpack-cli/compare/webpack-cli@6.0.1...webpack-cli@7.0.1)

---
updated-dependencies:
- dependency-name: webpack-cli
  dependency-version: 7.0.1
  dependency-type: direct:development
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

services/backend/package.json

@@ -83,7 +83,7 @@
     "typescript-eslint": "^8.56.1",
     "vitest": "^3.2.4",
     "webpack": "^5.105.2",
-    "webpack-cli": "^6.0.1",
+    "webpack-cli": "^7.0.1",
     "webpack-node-externals": "^3.0.0"
   }
 }