reduce amount of layers when building

app/Dockerfile

@@ -1,16 +1,18 @@
 FROM alpine:3.13
 EXPOSE 9000/tcp
 
-RUN apk add --no-cache dcron php8 php8-fpm \
-	php8-pdo php8-gd php8-pgsql php8-pdo_pgsql php8-mbstring \
-	php8-intl php8-xml php8-curl php8-session php8-tokenizer \
-	php8-dom php8-fileinfo php8-json php8-iconv \
-	php8-pcntl php8-posix php8-zip php8-openssl \
-	git postgresql-client sudo php8-pecl-xdebug
-
 ENV SCRIPT_ROOT=/opt/tt-rss
 
-RUN mkdir -p /var/www ${SCRIPT_ROOT}/config.d
+RUN apk add --no-cache dcron php8 php8-fpm \
+	php8-pdo php8-gd php8-pgsql php8-pdo_pgsql \
+	php8-mbstring php8-intl php8-xml php8-curl \
+	php8-session php8-tokenizer php8-dom php8-fileinfo \
+	php8-json php8-iconv php8-pcntl php8-posix php8-zip \
+	php8-openssl git postgresql-client sudo php8-pecl-xdebug && \
+	sed -i.bak 's/^listen = 127.0.0.1:9000/listen = 9000/' /etc/php8/php-fpm.d/www.conf && \
+	sed -i.bak 's/\(memory_limit =\) 128M/\1 256M/' /etc/php8/php.ini && \
+	sed -i.bak 's/;clear_env = .*/clear_env = no/i' /etc/php8/php-fpm.d/www.conf && \
+	mkdir -p /var/www ${SCRIPT_ROOT}/config.d
 
 ADD startup.sh ${SCRIPT_ROOT}
 ADD updater.sh ${SCRIPT_ROOT}
@@ -19,10 +21,6 @@ ADD dcron.sh ${SCRIPT_ROOT}
 ADD backup.sh /etc/periodic/weekly/backup
 ADD config.docker.php ${SCRIPT_ROOT}
 
-RUN sed -i.bak 's/^listen = 127.0.0.1:9000/listen = 9000/' /etc/php8/php-fpm.d/www.conf
-RUN sed -i.bak 's/\(memory_limit =\) 128M/\1 256M/' /etc/php8/php.ini
-RUN sed -i.bak 's/;clear_env = .*/clear_env = no/i' /etc/php8/php-fpm.d/www.conf
-
 ENV OWNER_UID=1000
 ENV OWNER_GID=1000