Add upi-installer base_images for disconnected workflow dependency

The ipi-aws-pre-disconnected chain's mirror-images-by-oc-adm step
requires the upi-installer image. Add it as a base_images entry
in z-stream configs for 4.16-4.21 to match the nightly configs.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: kasturinarra

ci-operator/config/openshift/lvm-operator/openshift-lvm-operator-release-management__zstream-4.16.yaml

@@ -1,3 +1,8 @@
+base_images:
+  upi-installer:
+    name: "4.16"
+    namespace: ocp
+    tag: upi-installer
 build_root:
   image_stream_tag:
     name: builder

ci-operator/config/openshift/lvm-operator/openshift-lvm-operator-release-management__zstream-4.18.yaml

@@ -1,3 +1,8 @@
+base_images:
+  upi-installer:
+    name: "4.18"
+    namespace: ocp
+    tag: upi-installer
 build_root:
   image_stream_tag:
     name: builder

ci-operator/config/openshift/lvm-operator/openshift-lvm-operator-release-management__zstream-4.19.yaml

@@ -1,3 +1,8 @@
+base_images:
+  upi-installer:
+    name: "4.19"
+    namespace: ocp
+    tag: upi-installer
 build_root:
   image_stream_tag:
     name: builder

ci-operator/config/openshift/lvm-operator/openshift-lvm-operator-release-management__zstream-4.20.yaml

@@ -1,3 +1,8 @@
+base_images:
+  upi-installer:
+    name: "4.20"
+    namespace: ocp
+    tag: upi-installer
 build_root:
   image_stream_tag:
     name: builder

ci-operator/config/openshift/lvm-operator/openshift-lvm-operator-release-management__zstream-4.21.yaml

@@ -1,3 +1,8 @@
+base_images:
+  upi-installer:
+    name: "4.21"
+    namespace: ocp
+    tag: upi-installer
 build_root:
   image_stream_tag:
     name: builder