qa: re-order composer installation and default PHP version handling

The current PHP default version was determine from the `composer.json` **after** `composer install` was called. With `composer install` (prior setting default PHP version) that will be the last installed PHP version via `apt`. This reorder should actually ensure that we do not accidentally have a newer version used to install composer dependencies.

Signed-off-by: Maximilian Bösing <[email protected]>

Author: boesing

Dockerfile

@@ -271,22 +271,22 @@ COPY composer.json \
     composer.lock \
     /tools/
 
-RUN cd /tools \
-    # Install `ext-bcmath` as it seems to be a requirement for `roave/backward-compatibility-check`
-    && apt install -y php-bcmath \
-    && composer install \
-        --classmap-authoritative
-
 # Set default PHP version based on the `composer.json` `config.platform.php` setting
 RUN export DEFAULT_PHP_VERSION=$(jq -r '.config.platform.php | sub("(?<minor>[0-9.]).99$"; "\(.minor)")' /tools/composer.json) \
-    # Cleanup composer files from external tools folder
-    && rm /tools/composer.* \
     && update-alternatives --set php /usr/bin/php$DEFAULT_PHP_VERSION \
     && update-alternatives --set phpize /usr/bin/phpize$DEFAULT_PHP_VERSION \
     && update-alternatives --set php-config /usr/bin/php-config$DEFAULT_PHP_VERSION \
     && update-alternatives --set phpdbg /usr/bin/phpdbg$DEFAULT_PHP_VERSION \
     && echo "DEFAULT_PHP_VERSION=${DEFAULT_PHP_VERSION}" >> /etc/environment
 
+RUN cd /tools \
+    # Install `ext-bcmath` as it seems to be a requirement for `roave/backward-compatibility-check`
+    && apt install -y php-bcmath \
+    && composer install \
+        --classmap-authoritative \
+    # Cleanup composer files from external tools folder
+    && rm /tools/composer.* \
+
 # Copy staabm/annotate-pull-request-from-checkstyle to external-tools stage
 RUN ln -s /tools/vendor/bin/cs2pr /usr/local/bin/cs2pr