`quick_start.sh` demo fails with Spack 1.1.1 on top of EESSI 2025.06 because zlib@1.2.13 was not found

[boegel]

When taking the quick_start.sh demo for a spin with EESSI 2025.06 (and Spack 1.1.1), I noticed it fails, as follows:

...
 • Bootstrapping Spack...
 • Detecting EESSI compat layer packages...
   $ spack external find --all -p /cvmfs/software.eessi.io/versions/2025.06/compat/linux/aarch64 --exclude gcc
==> The following specs have been detected on this system and added to /home/boegel.guest/spood/demo_spood/packages.yaml
-- no arch / no compilers ---------------------------------------
bash@5.2.37  bzip2@1.0.8  grep@3.12  sed@4.9  tar@1.35
   $ spack external find --all -p /cvmfs/software.eessi.io/versions/2025.06/compat/linux/aarch64/usr --exclude gcc
==> The following specs have been detected on this system and added to /home/boegel.guest/spood/demo_spood/packages.yaml
-- no arch / no compilers ---------------------------------------
autoconf@2.72    bison@3.8.2    curl@8.14.0     findutils@4.10.0  gettext@0.23.1  gnupg@2.4.8   libtool@2.5.4  ninja@1.12.1   pkgconf@2.4.3   rsync@3.4.1    which@2.23     zlib@1.3.1
automake@1.18    cmake@4.0.2    diffutils@3.12  flex@2.6.4        git@2.49.0      gpgme@1.24.3  m4@1.4.20      openssl@3.5.0  python@3.13.4   sqlite@3.50.0  win-file@5.46
binutils@2.44.0  coreutils@9.7  file@5.46       gawk@5.3.2        gmake@4.4.1     groff@1.23.0  meson@1.8.1    perl@5.40.2    rdma-core@57.0  texinfo@7.2    xz@5.8.2

============  Setup Complete  ============

  To use this demo Spack installation, run:

    export SPACK_USER_CONFIG_PATH=/home/boegel.guest/spood/demo_spood
    export SPACK_USER_CACHE_PATH=/home/boegel.guest/spood/demo_spood/cache

  Spack config directory:   /home/boegel.guest/spood/demo_spood"
  Spack install directory:  /home/boegel.guest/spood/demo_spood/opt"
  Spack modules directory:  /home/boegel.guest/spood/demo_spood/modules"

============  Demo Commands  ============
 1. List configured external packages:
   $ spack find -p --show-configured-externals

==> Warning: Spack is trying attach a Python dependency to 'meson@=1.8.1 build_system=python_pip platform=linux os=rocky9 target=aarch64'. This feature is deprecated, and will be removed in v1.2. Please make the dependency explicit in your configuration.
==> Error: the spec 'curl@8.3.0+nghttp2 target=haswell' depends on 'zlib@1.2.13', but there is no such external spec in packages.yaml [/home/boegel.guest/spood/demo_spood/packages.yaml:37]

EESSI 2025.06 doesn't provide zlib 1.2.13 in the compat layer, only zlib 1.3.1.