This avoids to adding const to the function type in a function pointer while enabling `Span<FunctionType*>(Span<FunctionType*>)` ctor. `Span<const FunctionType*>` should be considered invalid. The warning: https://learn.microsoft.com/en-us/cpp/error-messages/compiler-warnings/compiler-warning-level-1-c4180?view=msvc-170 Pull Request: https://projects.blender.org/blender/blender/pulls/134425