fix: make sheriff the entrypoint of the docker image

Author: scastlara

Dockerfile

@@ -24,3 +24,5 @@ WORKDIR /app
 COPY --from=osv-scanner /osv-scanner /usr/local/bin/osv-scanner
 COPY --from=builder /etc/ssl/certs/ca-certificates.crt /etc/ssl/certs/
 COPY --from=builder /app/build/sheriff /usr/local/bin/sheriff
+
+ENTRYPOINT [ "sheriff" ]