Bump openid-client from 6.7.1 to 6.8.0

Bumps [openid-client](https://github.com/panva/openid-client) from 6.7.1 to 6.8.0.
- [Release notes](https://github.com/panva/openid-client/releases)
- [Changelog](https://github.com/panva/openid-client/blob/main/CHANGELOG.md)
- [Commits](panva/openid-client@v6.7.1...v6.8.0)

---
updated-dependencies:
- dependency-name: openid-client
  dependency-version: 6.8.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

package-lock.json

@@ -81,7 +81,7 @@
     "next": "15.5.3",
     "next-auth": "^5.0.0-beta.29",
     "nhsuk-react-components": "^5.0.0",
-    "openid-client": "^6.7.1",
+    "openid-client": "^6.8.0",
     "pino": "^9.9.5",
     "react": "^19.1.1",
     "react-dom": "^19.1.1",