CARRY: add separate file for RHOAI build and update multarch base image

Signed-off-by: Kevin <kpostlet@redhat.com>

build/images/training-operator/Dockerfile.multiarch

@@ -1,4 +1,4 @@
-FROM registry.access.redhat.com/ubi8/ubi-minimal:8.9
+FROM registry.access.redhat.com/ubi9/ubi-minimal:latest
 ARG TARGETARCH
 WORKDIR /
 COPY ./manager-${TARGETARCH} ./manager

build/images/training-operator/Dockerfile.rhoai

@@ -0,0 +1,25 @@
+# Build the manager binary
+FROM registry.access.redhat.com/ubi9/go-toolset:1.20.10 as builder
+
+WORKDIR /workspace
+# Copy the Go Modules manifests
+COPY go.mod go.mod
+COPY go.sum go.sum
+# cache deps before building and copying source so that we don't need to re-download as much
+# and so that source changes don't invalidate our downloaded layer
+RUN go mod download
+
+# Copy the go source
+COPY . .
+
+# Build
+USER root
+RUN CGO_ENABLED=1 GOOS=linux GO111MODULE=on go build -tags strictfipsruntime -a -o manager cmd/training-operator.v1/main.go
+
+# Use distroless as minimal base image to package the manager binary
+# Refer to https://github.com/GoogleContainerTools/distroless for more details
+FROM registry.access.redhat.com/ubi9/ubi-minimal:latest
+WORKDIR /
+COPY --from=builder /workspace/manager .
+USER 65532:65532
+ENTRYPOINT ["/manager"]