Update install command in README.md

[bostrt]

I'm trying to install on Fedora 38 and RHEL 9.2 where uname -o returns GNU/Linux and doesn't work with the install command.

Using just uname works good but I'm unable to confirm on MacOS.

[rbost@fedora yank]$ uname -r
6.6.6-100.fc38.x86_64
[rbost@fedora yank]$ uname -o
GNU/Linux

bash-5.1$ uname -r
5.14.0-284.41.1.el9_2.x86_64
bash-5.1$ uname -o
GNU/Linux

[gmeghnag]

Thank you for the PR!