EXTERN: Adapt to Conan 2.0
Summary
https://gitlab.com/linkahead/linkahead-cpplib/-/issues/7
WARN: *** Conan 1 is legacy and on a deprecation path ***
WARN: *** Please upgrade to Conan 2 ***
See the migration guide.
Also, using Conan 2 allows using the extensions for CLion and Visual Studio.
Edited by Joscha Schmiedt