fix: custom/mongo-utils/Dockerfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-ALPINE315-LIBRETLS-2428776
- https://snyk.io/vuln/SNYK-ALPINE315-OPENSSL-2426331
- https://snyk.io/vuln/SNYK-ALPINE315-OPENSSL-3314621
- https://snyk.io/vuln/SNYK-ALPINE315-OPENSSL-3314622
- https://snyk.io/vuln/SNYK-ALPINE315-ZLIB-2976173

custom/mongo-utils/Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine:3.15.0
+FROM alpine:3.16
 RUN apk update && \
     apk upgrade --update-cache --available
 RUN echo 'http://dl-cdn.alpinelinux.org/alpine/v3.9/main' >> /etc/apk/repositories