uv

659e86ef - uv-pep508: add more routines for manipulating extras

uv-pep508: add more routines for manipulating extras In the course of working on #9289, I've had to devise some additions to our markers. While we are still staying strictly compatible with the PEP 508 format, we will be abusing the `extra` expression to carry a lot more information. Specifically, we want the following additional operations: * Simplify `extra != 'foo'` * Remove all extra expressions * Remove everything except extra expressions My work on #9289 requires all of these (which will be in a future in PR).