Fix substitution?

Dockerfile

@@ -1,4 +1,4 @@
-ARG POSTGRES_VERSION=latest
+ARG POSTGRES_VERSION=17
 
 FROM postgres:$POSTGRES_VERSION
 
@@ -11,6 +11,6 @@ RUN install -d /usr/share/postgresql-common/pgdg
 RUN curl -o /usr/share/postgresql-common/pgdg/apt.postgresql.org.asc --fail https://www.postgresql.org/media/keys/ACCC4CF8.asc
 RUN sh -c 'echo "deb [signed-by=/usr/share/postgresql-common/pgdg/apt.postgresql.org.asc] https://apt.postgresql.org/pub/repos/apt bookworm-pgdg main" > /etc/apt/sources.list.d/pgdg.list'
 RUN apt-get update
-RUN apt-get install postgresql-server-dev-${POSTGRES_VERSION} -y
-RUN sh -c 'export PATH=/usr/lib/postgresql/${POSTGRES_VERSION}/bin:$PATH'
-RUN apt-get install postgresql-${POSTGRES_VERSION}-wal2json -y
+RUN apt-get install postgresql-server-dev-$POSTGRES_VERSION -y
+RUN sh -c 'export PATH=/usr/lib/postgresql/$POSTGRES_VERSION/bin:$PATH'
+RUN apt-get install postgresql-$POSTGRES_VERSION-wal2json -y