buildx failed with: ERROR: failed to solve: process "/bin/sh -c set -e -x; echo 'Acquire::Retries \"3\";' > /etc/apt/apt.conf.d/80-retries; apt-get update; apt-get install -y --no-install-recommends ca-certificates python3-yaml cmake pkg-config make gcc g++ curl lcov clang clang-tidy clang-format cppcheck iwyu git file dpkg-dev util-linux; apt-get install -y --no-install-recommends libclang-rt-dev || true; apt-get install -y --no-install-recommends valgrind || true; sed -i '/pam_rootok.so$/aauth sufficient pam_permit.so' /etc/pam.d/su; git config --system --add safe.directory '*'" did not complete successfully: exit code: 100

The Ubuntu-20.04 brownout takes place from 2025-02-01. For more details, see https://github.com/actions/runner-images/issues/11101