[user-authn] Fix CVEs

[Jabejixo]

Description

This PR fixes:

• CVE-2025-65637
• CVE-2025-47914
• CVE-2025-58181

This PR updates Go dependencies in user-authn module images to address the listed CVEs.

Why do we need it, and what problem does it solve?

It removes known vulnerabilities from the user-authn module container images by updating affected dependencies, reducing security risk for clusters.

Why do we need it in the patch release (if we do)?

Not necessarily.

Checklist

• The code is covered by unit tests.
• e2e tests passed.
• Documentation updated according to the changes.
• Changes were tested in the Kubernetes cluster manually.

Changelog entries

section: user-authn
type: fix
summary: Fixed multiple CVEs in user-authn module images by updating dependencies.
impact_level: default