chore: Use bitnami docker image for kubectl

Dockerfile

@@ -19,13 +19,9 @@ ARG ARCH
 FROM golang:1.23@sha256:540d3442f4758da82e787d03930bf6468cf6f8613474135e8946259b9e531ea0 AS builder
 
 WORKDIR /workspace
-# Add kubectl tool
+
 # Using the $ARCH in the name of the binary here ensures we don't get any cross-arch caching after this binary is downloaded.
 ARG ARCH
-# kubectl latest version can be retrieved by curl -L -s https://dl.k8s.io/release/stable.txt
-ARG KUBECTL_VERSION=v1.31.1
-RUN curl -L "https://dl.k8s.io/release/${KUBECTL_VERSION}/bin/linux/${ARCH}/kubectl" -o kubectl-${ARCH} && \
-    chmod +x ./kubectl-${ARCH}
 
 # Copy the Go Modules manifests
 COPY go.mod go.mod
@@ -51,15 +47,19 @@ RUN --mount=type=cache,target=/go/pkg/mod \
     --mount=type=cache,target=/root/.cache/go-build \
     CGO_ENABLED=0 GOOS=linux GOARCH=${ARCH} go build -ldflags="${LDFLAGS}" -gcflags="${GCFLAGS}" -o manager main.go
 
+FROM --platform=linux/${ARCH} bitnami/kubectl:1.31.1 AS kubectl
+
 FROM --platform=linux/${ARCH} registry.access.redhat.com/ubi8-micro:8.10
 
 ARG ARCH
 
 WORKDIR /
 COPY --from=builder /workspace/manager .
-COPY --from=builder /workspace/kubectl-${ARCH} /usr/local/bin/kubectl
 COPY --from=builder /workspace/crds /crds
 
+# Copy the kubectl binary
+COPY --from=kubectl /opt/bitnami/kubectl/bin/kubectl /usr/local/bin/
+
 # Default Certificates are missing in micro-ubi. These are need to fetch DOCA drivers image tags
 COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem
 COPY /webhook-schemas /webhook-schemas