Fix Docker python3 dependency version

Author: fulghum

testing/PostgresDockerfile

@@ -13,7 +13,7 @@ RUN apt update -y && \
     curl -fsSL https://www.postgresql.org/media/keys/ACCC4CF8.asc | gpg --dearmor -o /etc/apt/trusted.gpg.d/postgresql.gpg
 RUN apt update -y && \
     apt install -y \
-    python3.8 \
+    python3 \
     python3-pip \
     python3-psycopg2 \
     curl \