Restore numpy > 1.21 compatibility

See for details:
#52

Release GIL in C++ code

See for details:
#50

Refresh for 2026 + build fixes

Thanks @bluemellophone!

See for details:
#47
#49

Refresh for 2026

From @bluemellophone:

This PR updates this project's codebase for 2026 and fixes pip installation failures.

See for more information: #47

v1.0.6

Include missing source files

v1.0.5

New heuristics by @peterchenadded for better-looking paths on uniform-cost grids

v1.0.4

Merge pull request #34 from hjweide/publish-source

Publish source package too

v1.0.3

Publish wheels to pypi on release