fix: arm64 image is actually x86 (#423)

Signed-off-by: Nham Le <lehoainham@gmail.com>
Co-authored-by: Brian Davis <dbrian@vmware.com>

Author: nhamlh

Dockerfile

@@ -18,7 +18,7 @@ COPY Makefile .
 ARG VERSION
 RUN make build VERSION=$VERSION TARGETARCH=$TARGETARCH TARGETOS=$TARGETOS
 
-FROM --platform=${BUILDPLATFORM:-linux/amd64} photon:4.0
+FROM --platform=${TARGETPLATFORM:-linux/amd64} photon:4.0
 
 ARG RVM_PATH=/usr/local/rvm
 ARG RUBY_VERSION=ruby-3.1.4
@@ -127,4 +127,4 @@ EXPOSE 24444 5140
 
 USER root
 
-ENTRYPOINT ["/fluentd/entrypoint.sh"]
+ENTRYPOINT ["/fluentd/entrypoint.sh"]