Using apt-get instead of unstable apt command in dockerfile

Dockerfile

@@ -40,11 +40,11 @@ WORKDIR /opt/core
 
 COPY requirements.txt .
 
-RUN apt update && \
-    apt install --no-install-recommends -y \
-    libpq-dev wait-for-it && \
-    apt autoremove -y && \
-    apt clean && \
+RUN apt-get update && \
+    apt-get install --no-install-recommends -y \
+        libpq-dev wait-for-it && \
+    apt-get autoremove -y && \
+    apt-get clean && \
     rm -rf /var/lib/apt/lists/* /tmp/* /var/tmp/* && \
     pip3 install --no-cache-dir -r requirements.txt