Revert "fix: try to manually raise memory limits before execution"

This reverts commit bc81c0f5.

This doesn't really affect pipelines and thus can be safely removed. The
issue with memory limits is due to forking process while generating
translations, not due to improper environment variables interpretation.

includes/prepare.yml

@@ -61,9 +61,9 @@ prepare translations:
       - $IS_NPM_LIBRARY
   interruptible: true
   script:
-    - COMPOSER_MEMORY_LIMIT=-1 composer generate-pot
-    - COMPOSER_MEMORY_LIMIT=-1 composer merge-translations
-    - COMPOSER_MEMORY_LIMIT=-1 composer generate-pot
+    - composer generate-pot
+    - composer merge-translations
+    - composer generate-pot
 
 prepare tests:
   image: wpdesknet/phpunit-woocommerce:0-0