net/traefik: Update to upstream release 3.4.0
Details:
- Update to 3.4.x branch, see: https://github.com/traefik/traefik/releases/tag/v3.4.0
- While most configurations are expected to continue to work, a change in the Kubernetes CRD provider may require manual config updates for HTTP load balancing: https://doc.traefik.io/traefik/master/migration/v3/#v33-to-v34
MFH: 2025Q2
(cherry picked from commit 682ab660935dae162e96dc7b0510d3aea108d1b8)