Restrict LibCImGui.jl compat bounds

[JamesWrigley]

This is so that we don't inadvertently break things while updating all the packages 😅 If you agree, I think a new patch release could be made for this.

[Gnimuc]

Is this really necessary?

"1.82.2" => [1.82.2, 1.83.0)
~~"~1.82" => [1.82.0, 1.83.0)~~

oh, it's actually:

"1.82.2" => [1.82.2, 2.0.0)
"~1.82" => [1.82.0, 1.83.0)

[JamesWrigley]

Yeah exactly, the idea is that hopefully (:pray:) patch versions will always be compatible.