Issue template asking for baseline information

[zachcran]

Is your feature request related to a problem? Please describe.
Since CMake is very cross-platform, and I doubt everyone religiously updates their CMake installations, there are many combinations of operating systems and CMake versions that people may report issues from. This is especially relevant now that a new major version of CMake (4.0) has been released; the first new major release in over a decade.

Describe the solution you'd like
We should include two information requests in the "Bug Report" issue template:

1. What operating system are you using?
2. What version of CMake are you using?

Additionally, it would be useful to provide an example or two of how to get that information. As a first draft, I am thinking the addition to the template could look something like the following. I'm happy to iterate on this until we have something we are happy with adding!

Baseline Information

• Operating system (Windows <10/11/etc>, macOS <version>, GNU/Linux uname -a):
• CMake version (output of cmake --version):