feat: Added support for arm in dockerfile (#2180)

* Added support for arm in dockerfile

* Removed echo statement

* Capitalised arch variable

Dockerfile

@@ -18,7 +18,8 @@ ARG KUBECTL_VERSION="v1.25.2"
 COPY --from=build /k9s/execs/k9s /bin/k9s
 RUN apk add --update ca-certificates \
   && apk add --update -t deps curl vim \
-  && curl -L https://storage.googleapis.com/kubernetes-release/release/${KUBECTL_VERSION}/bin/linux/amd64/kubectl -o /usr/local/bin/kubectl \
+  && TARGET_ARCH=$(arch | sed s/aarch64/arm64/ | sed s/x86_64/amd64/) \
+  && curl -L https://storage.googleapis.com/kubernetes-release/release/${KUBECTL_VERSION}/bin/linux/${TARGET_ARCH}/kubectl -o /usr/local/bin/kubectl \
   && chmod +x /usr/local/bin/kubectl \
   && apk del --purge deps \
   && rm /var/cache/apk/*