Remove ca-certificates in the final image (#41)

Dockerfile

@@ -1,7 +1,7 @@
 # Based off of https://github.com/tembo-io/pgmq/blob/main/images/pgmq-pg/Dockerfile
 ARG PG_MAJOR_VERSION=16
 
-FROM postgres:${PG_MAJOR_VERSION}-bookworm as build
+FROM postgres:${PG_MAJOR_VERSION}-bookworm AS build
 
 ARG PG_MAJOR_VERSION=16
 
@@ -36,9 +36,4 @@ ARG PG_MAJOR_VERSION=16
 COPY --from=build /usr/share/postgresql/${PG_MAJOR_VERSION}/extension /usr/share/postgresql/${PG_MAJOR_VERSION}/extension
 COPY --from=build /usr/lib/postgresql/${PG_MAJOR_VERSION}/lib /usr/lib/postgresql/${PG_MAJOR_VERSION}/lib
 
-RUN apt-get update && apt-get install -y --no-install-recommends \
-    ca-certificates \
-    && apt-get clean \
-    && rm -rf /var/lib/apt/lists/*
-
 USER postgres