Composer itself is using a lot of memory on resolving version constraints on composer update.
This issue is about making sure we limit amount of packages versions it needs to calculate matches for, by having more specific version constraints.

Related (but different) issue:

• EZS-1134 On composer install, Composer buffers packages in memory and consumes a lot of memory on packages with lots of binary content
• Next Composer version: https://github.com/composer/composer/pull/6168 "Improve memory usage resolving dependencies"