Apply suggestions from code review

Co-authored-by: Michael Shen <[email protected]>

tooling/image-sync/Dockerfile

@@ -1,16 +1,13 @@
-# Base and builder image will need to be replaced by Fips compliant one
 FROM --platform=${TARGETPLATFORM:-linux/amd64} mcr.microsoft.com/oss/go/microsoft/golang:1.22-fips-cbl-mariner2.0@sha256:d024591e53909d3f5d9f27cde4e1fea45f32963d97711042db36a499779630f8 as builder
 
 WORKDIR /app
 ADD . .
 # https://github.com/microsoft/go/tree/microsoft/main/eng/doc/fips#build-option-to-require-fips-mode
 ENV CGO_ENABLED=1 GOFLAGS='-tags=requirefips'
 
-RUN tdnf install -y gpgme-devel; \
-    tdnf clean all; \
-    make image-sync
+RUN make image-sync
 
-FROM --platform=${TARGETPLATFORM:-linux/amd64} mcr.microsoft.com/cbl-mariner/base/core:2.0-nonroot@sha256:fac93debd6c88c9935fdb85e08c3a57e601124018b87015635f50549b6527f5a
+FROM --platform=${TARGETPLATFORM:-linux/amd64} mcr.microsoft.com/cbl-mariner/distroless/base:2.0-nonroot@sha256:ef0dc582fc2a8dd34fbb41341a3a9a1aaa70d4542ff04ce4e33a641e52e4807e
 WORKDIR /
 
 COPY --from=builder /app/image-sync .