[requirements][stable] Capping requirements in stable branches

Hi, I have a question on version capping in requirements files in stable branches. When some newer version of dependent library does not work with my project, do we accept a patch to add version capping of the library in stable branches? For example, the horizon team received a patch to novaclient to <16 [1]. novaclient 16.0.0 was released after Train release, so there is no surprise that we don't have the version cap novaclient<16 in Train release. My understanding is that we don't usually cap versions of libraries after the release, but I am sending this mail to check our general guideline. Thanks, Akihiro Motoki (irc: amotoki) [1] https://review.opendev.org/#/c/693000/