util/dynamic_library: Add missing include for <memory>
Fixes the following compile error seen with GCC 10.2 (Void Linux):
In file included from ../src/biometry/util/dynamic_library.cpp:20:
../src/biometry/util/dynamic_library.h:99:31: error: 'shared_ptr' in namespace 'std' does not name a template type
99 | DynamicLibrary(const std::shared_ptr<Api>& api, const boost::filesystem::path& path);
| ^~~~~~~~~~
../src/biometry/util/dynamic_library.h:27:1: note: 'std::shared_ptr' is defined in header '<memory>'; did you forget to '#include <memory>'?
26 | #include <boost/filesystem.hpp>
+++ |+#include <memory>
27 |
This should also fix the FTBFS seen on Debian as reported by @sunweaver.
Reference: https://en.cppreference.com/w/cpp/memory/shared_ptr