py-pybind11: update to 3.0.0

[Schamschula]

Description

py-pybind11 3.0.0 implements a significant change in the build system.

It is blocking the update of py-pikepdf to version 9.10.0, which has made major code changes and now only builds against the new version of py-pybind11. See: https://github.com/Schamschula/macports/blob/master/python/py-pikepdf/Portfile

Note, however, I have not tested builds of all other dependent ports.

Type(s)

• enhancement

Tested on

macOS 15.5 24F74 arm64
Xcode 16.4 16F6

Verification

Have you

• followed our Commit Message Guidelines?
• checked that there aren't other open pull requests for the same change?
• checked your Portfile with port lint?
• tried a full install with sudo port -vst install?
• tested basic functionality of all binary files?

[macportsbot]

Notifying maintainers:
@stromnov for port py-pybind11.