Fixing github actions with composer image change

Author: dmols

build/nginx/Dockerfile.build

@@ -4,7 +4,7 @@ RUN apt-get update -y \
     && apt-get install -y nginx libpng-dev zlib1g-dev git unzip
 
 # PHP_CPPFLAGS are used by the docker-php-ext-* scripts
-ENV PHP_CPPFLAGS="$PHP_CPPFLAGS -std=c++11"
+ENV PHP_CPPFLAGS="$PHP_CPPFLAGS -std=c++17"
 
 RUN docker-php-ext-install pdo_mysql gd pdo \
     && docker-php-ext-install opcache \

build/nginx/Dockerfile.composer

@@ -1,5 +1,5 @@
-FROM composer
+FROM composer:2.6.4
 
 RUN apk add gd-dev libpng-dev
 RUN docker-php-ext-install gd
-WORKDIR /app
+WORKDIR /app