crond: Updates.

- Update Supercronic.
- Update the base image.

crond/Dockerfile

-FROM alpine:3.16 as downloader
-ARG URL=https://github.com/aptible/supercronic/releases/download/v0.2.1/supercronic-linux-amd64
-ARG SHA1SUM=d7f4c0886eb85249ad05ed592902fa6865bb9d70
+FROM alpine:3.17 as downloader
+ARG URL=https://github.com/aptible/supercronic/releases/download/v0.2.3/supercronic-linux-amd64
+ARG SHA1SUM=dbed853c06aba2c611bbb1955b2c1667b51dcb0a
 WORKDIR /tmp
 RUN wget -q $URL && \
     echo "$SHA1SUM  supercronic-linux-amd64" > sha1.sum && \
@@ -8,7 +8,7 @@ RUN wget -q $URL && \
     install -m 755 supercronic-linux-amd64 /usr/local/bin/supercronic && \
     touch /crontab
 
-FROM alpine:3.16
+FROM alpine:3.17
 COPY --from=downloader /usr/local/bin/supercronic /usr/local/bin/supercronic
 COPY --from=downloader /crontab /crontab
 WORKDIR /tmp