^7.3|^7.4|^8 Version string '8' does not follow SemVer semantics

While this indeed isn't correct, there are many cases in composer where this exists.  It is possible to validate this but trigger a warning instead?  

Or have a "strict" mode?   This is the package I want to validate, but there are others.

https://packagist.org/packages/amorvan/responders-bundle

