multimedia/assimp: 3.1.1 -> 3.2

Changes:

https://github.com/assimp/assimp/compare/v3.1.1...v3.2

• Use source code from GitHub
• Remove check for zzip-zlib-config from cmake-modules/FindZLIB.cmake file
• Remove usage of git from CMakeLists.txt file
• Use sed patch to delete minizip check, instead of static patch
• Use patch for pstdint.h file to update it to newer version, which fixes build on FreeBSD
• Update pkg-plist file
• maintainer reset after three maintainer timeouts

PR: 209356
Submitted by: lightside@gmx.com
Approved by: yuri@tsoft.com (maintainer timeout)