Update Airshipctl pin, kustomize install condition

Updates the airshipctl pin to include a fix which enables deployment
of sites other than test-site:
https://review.opendev.org/c/airship/airshipctl/+/784436

Change-Id: Ia4f8d9048dc0fd0e3b7eb1e3734f37350a3d7110
(cherry picked from commit a13eb1f12b)

playbooks/airship-treasuremap-build-gate.yaml

@@ -36,7 +36,6 @@
       include_role:
         name: install-kustomize
 
-    # Installs kustomize plugin functionality needed for rendering below
     - name: install airshipctl
       shell: |
         cd {{ local_src_dir | default(zuul.project.src_dir) }}

tools/deployment/01_install_essentials.sh

@@ -29,4 +29,7 @@ cd ${AIRSHIPCTL_PROJECT}
 ./tools/deployment/provider_common/03_install_pip.sh
 ./tools/deployment/provider_common/04_install_yq.sh
 ./tools/deployment/01_install_kubectl.sh
-./tools/install_kustomize.sh
+if ! $(which kustomize > /dev/null); then
+  ./tools/install_kustomize.sh
+fi
+

zuul.d/projects.yaml

@@ -14,7 +14,7 @@
     vars:
       # NOTE(drewwalters96): Set AIRSHIPCTL_REF to a commit SHA in order to pin
       # the cloned version of airshipctl to a known/compatible reference.
-      AIRSHIPCTL_REF: "030bb123d8fedd39125dd6eae92f48e0d32a7469"
+      AIRSHIPCTL_REF: "892bb6a16d53a0f43571284db83901bef53ed440"
       sphinx_build_dir: docs/build
     check:
       jobs: