Install Composer in the dev container properly.

Author: Crell

docker/php/81/Dockerfile

@@ -1,10 +1,7 @@
-FROM php:8.1.4-cli
+FROM php:8.1-cli
 WORKDIR /usr/src/myapp
 
+COPY --from=composer:latest /usr/bin/composer /usr/bin/composer
+
 RUN apt-get update && apt-get install zip unzip git -y \
-    && pecl install xdebug \
-    && php -r "copy('https://getcomposer.org/installer', 'composer-setup.php');" \
-    && php -r "if (hash_file('sha384', 'composer-setup.php') === '906a84df04cea2aa72f40b5f787e49f22d4c2f19492ac310e8cba5b96ac8b64115ac402c8cd292b8a03482574915d1a8') { echo 'Installer verified'; } else { echo 'Installer corrupt'; unlink('composer-setup.php'); } echo PHP_EOL;" \
-    && php composer-setup.php --install-dir=/usr/bin --filename=composer \
-    && php -r "unlink('composer-setup.php');" \
-    && mkdir /.composer && chmod 777 /.composer
+    && pecl install xdebug