Fix issues with spack install on infra-update-v8

[penguian]

Closes #28

Tested on Gadi:

==> Installing access-ram3-latest-xckkfkc6khfe4lu6yllwtfnn5pchehge [24/24]
==> No patches needed for access-ram3
==> access-ram3: Executing phase: 'install'
==> access-ram3: Successfully installed access-ram3-latest-xckkfkc6khfe4lu6yllwtfnn5pchehge
  Stage: 0.00s.  Install: 0.00s.  Post-install: 0.16s.  Total: 1.03s
[+] /g/data/tm70/pcl851/spack/1.1/release/linux-x86_64_v4/access-ram3-latest-xckkfkc6khfe4lu6yllwtfnn5pchehge
==> Updating view at /g/data/tm70/pcl851/spack/1.1/environments/access-ram3/.spack-env/view

[penguian]

Also tested with +DR_HOOK: Building with um: require: ['+DR_HOOK'] (which pulls in fiat@um) also succeeds — 26/26 packages installed:

==> Installing fiat-um-v7cgupoh42xoiadvjgpdhopyu6oauc25 [20/26]
==> Applied patch .../fiat/intel_warnings_v120.patch
==> fiat: Successfully installed fiat-um-v7cgupoh42xoiadvjgpdhopyu6oauc25

...

==> Installing access-ram3-latest-dccynig54cp7gojdckjczf2p6vwo6zmp [26/26]
==> access-ram3: Successfully installed access-ram3-latest-dccynig54cp7gojdckjczf2p6vwo6zmp

The fiat Intel warnings patch (intel_warnings_v120.patch) is correctly applied to the @um version.