[libgmp] upgrade 6.1.2 -> 6.2.1 for initial arm64 support
Upgrade libgmp to the version with initial arm64 support.
A part of the effort to upstream changes needed for macos arm64 native kdenlive.
Question: Is it generally recommended to keep previous versions in the blueprint as I did in the commit or do you prefer to have just one version there and add more only in cases where you observe incompatibilities with software using the library as a dependency?
Edited by Mario Hros