Upgrade hypatia with Ubuntu 24.04 and compatible with ns3-3.45

[c1ydehhx]

Hi, I'm Clyde from National Yang Ming Chiao Tung University, Taiwan. I would like to contribute hypatia with upgrade available OS version and support latest ns3.

I doing a patch to support Ubuntu 24.04 and latest ns3:

• Modify hypatia_install_dependency.sh to support virtual python environment and install old dependency.
• Modify .gitignore.
• Use python3 instead of python
• Compatible with ns3-3.45 version.
  • Use unordered_map to instead of sgi::hash_map
  • Use Ptr class to instead raw pointer.

The patched version can:

• No warning when build hypatia.
• passed the test in hypatia_run_tests.sh.

Please review it. Thanks!