OHDsi bundle build failing due to Debian Bullseye packages returning 404

I'm deploying Azure TRE v0.29.0 and the OHDsi workspace service is currently failing during the bundle build.

I deployed the same version around two weeks ago without any issues, but it has now started failing when installing packages from the Debian Bullseye repositories.

The OHDsi Dockerfile currently uses:

FROM --platform=linux/amd64 debian:bullseye-slim

The failure happens at:

RUN apt-get update && apt-get install -y curl gnupg

Several packages are now returning 404 Not Found, for example:

E: Failed to fetch http://deb.debian.org/debian-security/pool/updates/main/o/openssl/openssl_1.1.1w-0%2bdeb11u8_amd64.deb
404 Not Found

E: Failed to fetch http://deb.debian.org/debian-security/pool/updates/main/c/curl/libcurl4_7.74.0-1.3%2bdeb11u16_amd64.deb
404 Not Found

E: Failed to fetch http://deb.debian.org/debian-security/pool/updates/main/g/gnupg2/gpg_2.2.27-2%2bdeb11u3_amd64.deb
404 Not Found

E: Unable to fetch some archives, maybe run apt-get update or try with --fix-missing?

This eventually causes the OHDsi bundle build to fail.

As Debian 11 Bullseye reached the end of LTS support on 31 August 2026, I wonder if the OHDsi Dockerfile now needs to be updated to use a newer supported Debian version, along with the corresponding Microsoft package repository.

Start with the OHDsi Dockerfile and reproduce the failure at the apt-get update && apt-get install step during the bundle build. Check the Debian base image and corresponding Microsoft package repository configuration, then verify that the bundle builds successfully and the required packages install without 404 errors.