fix: PG_MAJOR and PGDG repo for beta versions

Signed-off-by: Niccolò Fei <niccolo.fei@enterprisedb.com>

Author: NiccoloFei

Dockerfile

@@ -2,13 +2,13 @@ ARG BASE=debian:12.10-slim
 FROM $BASE AS minimal
 
 ARG PG_VERSION
-ARG PG_MAJOR=${PG_VERSION%%.*}
+ARG PG_MAJOR=${PG_VERSION%%[.~]*}
 
 ENV PATH=$PATH:/usr/lib/postgresql/$PG_MAJOR/bin
 
 RUN apt-get update && \
     apt-get install -y --no-install-recommends postgresql-common ca-certificates gnupg && \
-    /usr/share/postgresql-common/pgdg/apt.postgresql.org.sh -y && \
+    /usr/share/postgresql-common/pgdg/apt.postgresql.org.sh -y -c "${PG_MAJOR}" && \
     apt-get install -y --no-install-recommends -o Dpkg::::="--force-confdef" -o Dpkg::::="--force-confold" postgresql-common && \
     sed -ri 's/#(create_main_cluster) .*$/\1 = false/' /etc/postgresql-common/createcluster.conf && \
     apt-get install -y --no-install-recommends \