ci: install meson in CirrusCI KVM build environment

scripts/archive-source.sh needs meson in order to download the subprojects,
therefore meson needs to be part of the host environment in which VM-based
build jobs run.

Fixes: 2019cabfee0 ("meson: subprojects: replace submodules with wrap files", 2023-06-06)
Reported-by: Daniel P. Berrangé <berrange@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

.gitlab-ci.d/cirrus/kvm-build.yml

@@ -15,7 +15,7 @@ env:
     folder: $HOME/.cache/qemu-vm
   install_script:
     - dnf update -y
-    - dnf install -y git make openssh-clients qemu-img qemu-system-x86 wget
+    - dnf install -y git make openssh-clients qemu-img qemu-system-x86 wget meson
   clone_script:
     - git clone --depth 100 "$CI_REPOSITORY_URL" .
     - git fetch origin "$CI_COMMIT_REF_NAME"