build(deps): bump styled-components in /frontend/kesaseteli/handler

Bumps [styled-components](https://github.com/styled-components/styled-components) from 5.3.11 to 6.0.7.
- [Release notes](https://github.com/styled-components/styled-components/releases)
- [Commits](styled-components/styled-components@v5.3.11...v6.0.7)

---
updated-dependencies:
- dependency-name: styled-components
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

frontend/kesaseteli/handler/package.json

@@ -37,7 +37,7 @@
     "react-hook-form": "^7.30.0",
     "react-query": "^3.34.0",
     "react-toastify": "^9.0.4",
-    "styled-components": "^5.3.1",
+    "styled-components": "^6.0.7",
     "ts-node": "^10.0.0"
   },
   "devDependencies": {