Fix release tests are not working properly

Author: shinyaaa

.github/workflows/Dockerfile

@@ -68,6 +68,6 @@ RUN rpm -ivh /var/lib/pgsql/rpmbuild/RPMS/x86_64/*
 
 USER postgres
 RUN initdb --no-locale -E UTF8  && \
-    pg_ctl -w start
-RUN make -C pg_rman installcheck; exit 0
-RUN cat /var/lib/pgsql/pg_rman/regression.out
+    pg_ctl -w start && \
+    make -C pg_rman installcheck $$ \
+    cat /var/lib/pgsql/pg_rman/regression.out