Update Tekton output-image tags to version odh-v3.2 (#37)

Co-authored-by: github-actions[bot] <github-actions[bot]@users.noreply.github.com>

Author: odh-devops-app[bot]

.tekton/mlserver-push.yaml

@@ -8,7 +8,7 @@ metadata:
     pipelinesascode.tekton.dev/cancel-in-progress: "false"
     pipelinesascode.tekton.dev/max-keep-runs: "3"
     pipelinesascode.tekton.dev/on-cel-expression: event == "push" && target_branch
-      == "release/1.7.x"
+      == "release-1.7.x"
   creationTimestamp: null
   labels:
     appstudio.openshift.io/application: opendatahub-release
@@ -31,6 +31,8 @@ spec:
   - name: build-args
     value:
     - RUNTIMES=lightgbm sklearn xgboost
+    - BUILDER_BASE_IMAGE=python:3.12-slim
+    - RUNTIME_BASE_IMAGE=registry.access.redhat.com/ubi9/ubi-minimal
   pipelineSpec:
     description: |
       This pipeline is ideal for building container images from a Containerfile while maintaining trust after pipeline customization.