Change dockerfile to support php-7.3

Dockerfile

@@ -1,4 +1,4 @@
-FROM debian:bullseye
+FROM debian:buster
 
 # Set the env variables to non-interactive
 ENV DEBIAN_FRONTEND noninteractive
@@ -6,42 +6,43 @@ ENV DEBIAN_PRIORITY critical
 ENV DEBCONF_NOWARNINGS yes
 
 RUN apt-get update && apt-get -y install \
-    php7.4-memcached \
+    php7.3-memcached \
     php-redis \
-    php7.4-bcmath \
-    php7.4-bz2 \
-    php7.4-cli \
-    php7.4-common \
-    php7.4-curl \
-    php7.4-fpm \
-    php7.4-gmp \
-    php7.4-intl \
-    php7.4-json \
-    php7.4-mbstring \
-    php7.4-mysql \
-    php7.4-odbc \
-    php7.4-opcache \
-    php7.4-pgsql \
-    php7.4-readline \
-    php7.4-tidy \
-    php7.4-xml \
-    php7.4-xmlrpc \
-    php7.4-xsl \
-    php7.4-zip \
-    php7.4-gd \
+    php7.3-bcmath \
+    php7.3-bz2 \
+    php7.3-cli \
+    php7.3-common \
+    php7.3-curl \
+    php7.3-fpm \
+    php7.3-gmp \
+    php7.3-intl \
+    php7.3-json \
+    php7.3-mbstring \
+    php7.3-mysql \
+    php7.3-odbc \
+    php7.3-opcache \
+    php7.3-pgsql \
+    php7.3-readline \
+    php7.3-tidy \
+    php7.3-xml \
+    php7.3-xmlrpc \
+    php7.3-xsl \
+    php7.3-zip \
+    php7.3-gd \
     php-bcmath \
     php-apcu \
     php-cli \
     php-imagick \
     composer
 
-ADD ./www.conf /etc/php/7.4/fpm/pool.d/www.conf
-ADD ./php.ini /etc/php/7.4/fpm/
-ADD ./php-fpm.conf /etc/php/7.4/fpm/
+ADD ./www.conf /etc/php/7.3/fpm/pool.d/www.conf
+ADD ./php.ini /etc/php/7.3/fpm/
+ADD ./php.ini /etc/php/7.3/cli/
+ADD ./php-fpm.conf /etc/php/7.3/fpm/
 
 CMD [ \
-    "/usr/sbin/php-fpm7.4", \
+    "/usr/sbin/php-fpm7.3", \
     "--nodaemonize", \
     "--fpm-config", \
-    "/etc/php/7.4/fpm/php-fpm.conf" \
+    "/etc/php/7.3/fpm/php-fpm.conf" \
 ]