This PR allows downstream projects to use pkg-config to search for the libsecp256k1 library that is built with CMake.
Addressed https://github.com/bitcoin-core/secp256k1/discussions/1419#discussioncomment-6922896:
We could just ship the pkg-config file also in CMake builds.
This change allows downstream projects to use pkg-config to search for
the libsecp256k1 library that is built with CMake.
ACK https://github.com/bitcoin-core/secp256k1/pull/1422/commits/421d84855aeb9324b4f131c3e6c7ee8cf4f5f4e5 I compared the generated pc files and they match in autotools and CMake
(Well, they match except for the -dev suffix we have in autotools on non-release commits... but there's not really support for this in CMake, so it seems we have to live with this for now. https://gitlab.kitware.com/cmake/cmake/-/issues/16716 )