ci instability: TCP RST during bash source download

[jgehrcke]

A image/build job on main:

1.081 = downloading bash 5.2
1.081 File: bash-5.2.tar.gz | Url: https://ftpmirror.gnu.org//bash/bash-5.2.tar.gz
1.727 curl: (7) Failed to connect to mirror.cs.odu.edu port 443 after 55 ms: Connection refused
------
ERROR: failed to build: failed to solve: process "/bin/sh -c ARCH=\"$TARGETARCH\" && STRIP=strip &&     [ \"$ARCH\" = \"arm64\" ] && 

Logs: https://github.com/NVIDIA/k8s-dra-driver-gpu/actions/runs/18525921958/job/52796998430#step:8:2538

I saw such failures locally today and already worked on a patch: #676.

Only now I see that indeed CI was affected.

TCP RST is something we have to retry on, and not give up immediately. See #676.