Don't specify outdated diffusers version with ~= in requirements.txt

[NeedsMoar]

There are many other nodes for comfy and lately lots have been getting sloppy with new models and just using some pipeline from diffusers, which avoids doing much work but also avoids every optimization in comfy and all advantages of breaking everything into nodes in the first place. Anyway, the
diffusers~=0.21.4
should be a
diffusers>=0.21.4
so this node doesn't break the next node that comes along and needs a newer version. Actually I think the last time a node broke because of this, it was the fault of some other node and this was the broken one. ComfyUI manager honors the requirements so every time I updated, one of the heavily updated nodes would downgrade it. Then I'd have to kill the server, manually pull the an update to current diffusers, start it again, then everything worked until I updated again the next day. Not fun.

For right now I'm just going to remove this node, and keep track of when the models show up as single-file downloads and it's not using diffusers pipelines pulled from a repo.