fix: Dockerfile to reduce vulnerabilities

The following vulnerabilities are fixed with an upgrade:
- https://snyk.io/vuln/SNYK-ALPINE37-MUSL-458286
- https://snyk.io/vuln/SNYK-ALPINE37-MUSL-458286

Dockerfile

@@ -1,4 +1,4 @@
-FROM alpine:3.7
+FROM alpine:3.18.6
 RUN apk --update add postgresql-client && rm -rf /var/cache/apk/*
 COPY . /
 ENTRYPOINT ["./entrypoint.sh"]