Fix games/supertux on sparc64

supertux fails to build on sparc64 but helpfully says the following:

+note: 'std::unique_ptr' is defined in header '<memory>'; this is
+probably fixable by adding '#include <memory>'

So this patch adds that include and fixes the build on sparc64
without breaking the build on amd64.

ok?

--Kurt

Index: patches/patch-external_partio_zip_zip_manager_hpp
===================================================================
RCS file: patches/patch-external_partio_zip_zip_manager_hpp
diff -N patches/patch-external_partio_zip_zip_manager_hpp
--- /dev/null 1 Jan 1970 00:00:00 -0000
+++ patches/patch-external_partio_zip_zip_manager_hpp 4 Apr 2026 06:16:21 -0000
@@ -0,0 +1,14 @@
+note: 'std::unique_ptr' is defined in header '<memory>'; this is
+probably fixable by adding '#include <memory>'
+
+Index: external/partio_zip/zip_manager.hpp
+--- external/partio_zip/zip_manager.hpp.orig
++++ external/partio_zip/zip_manager.hpp
+@@ -47,6 +47,7 @@ OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY O
+ #include <string>
+ #include <stdexcept>
+ #include <vector>
++#include <memory>
+
+ namespace Partio{
+ struct ZipFileHeader;