Fix instaslice-operator build_root to use Go 1.23 (#74385)

PR #74222 changed the build_root image from golang-1.22 to
rhel-8-release-golang-1.22-openshift-4.18, but instaslice-operator
requires Go 1.23 (per go.mod). The rhel-8 image has GOTOOLCHAIN=local
which prevents auto-downloading Go 1.23, causing unit tests to fail with:

  go: go.mod requires go >= 1.23.0 (running go 1.22.9; GOTOOLCHAIN=local)

Update to rhel-9-release-golang-1.23-openshift-4.20 which has Go 1.23.

Co-authored-by: Claude Opus 4.5 <noreply@anthropic.com>

Author: harche

ci-operator/config/openshift-priv/instaslice-operator/openshift-priv-instaslice-operator-next.yaml

@@ -15,7 +15,7 @@ build_root:
   image_stream_tag:
     name: release
     namespace: openshift
-    tag: rhel-8-release-golang-1.22-openshift-4.18
+    tag: rhel-9-release-golang-1.23-openshift-4.20
 canonical_go_repository: github.com/openshift/instaslice-operator
 images:
 - dockerfile_literal: |

ci-operator/config/openshift/instaslice-operator/openshift-instaslice-operator-next.yaml

@@ -15,7 +15,7 @@ build_root:
   image_stream_tag:
     name: release
     namespace: openshift
-    tag: rhel-8-release-golang-1.22-openshift-4.18
+    tag: rhel-9-release-golang-1.23-openshift-4.20
 images:
 - dockerfile_literal: |
     FROM src