Python 3.15 support

[Houbein]

Python 3.15 RC1 is out and in feature freeze, no ABI changes will happen from this point and the full release is expected in 7 weeks.

[Nepitwin]

Build from python 3.15 is failed due missing Python.Net

ERROR: Ignored the following yanked versions: 3.0.0rc1, 3.0.0
ERROR: Ignored the following versions that require a different python version: 1.9.5 Requires-Python !=3.0.,!=3.1.,!=3.2.,!=3.3.,>=2.7,<3.7; 3.0.0.post1 Requires-Python >=3.7,<3.11; 3.0.1 Requires-Python >=3.7,<3.12; 3.0.2 Requires-Python >=3.7,<3.12; 3.0.3 Requires-Python >=3.7,<3.13; 3.0.4 Requires-Python >=3.7,<3.13; 3.0.5 Requires-Python >=3.7,<3.14; 3.1.0 Requires-Python >=3.10,<3.15; 3.1.0rc0 Requires-Python >=3.10,<3.15; 3.1.0rc1 Requires-Python >=3.10,<3.15; 6.0.0 Requires-Python ~=3.9,<3.14; 6.0.0a1 Requires-Python ~=3.9,<3.13; 6.0.0a2 Requires-Python ~=3.9,<3.14; 6.0.0a3 Requires-Python ~=3.9,<3.14; 6.0.0b1 Requires-Python ~=3.9,<3.14; 6.0.0b2 Requires-Python ~=3.9,<3.14
ERROR: Could not find a version that satisfies the requirement pythonnet>=3.0.0 (from versions: 2.0.0, 2.1.0.dev1, 2.1.0, 2.2.0.dev1, 2.2.1, 2.2.2, 2.3.0, 2.4.0rc2, 2.4.0, 2.5.0rc2, 2.5.0, 2.5.1, 2.5.2, 3.0.0a1, 3.0.0a2, 3.0.0rc2, 3.0.0rc3, 3.0.0rc4, 3.0.0rc5, 3.0.0rc6)
[notice] A new release of pip is available: 26.2 -> 26.2.1
[notice] To update, run: C:\projects\robotframework-flaui.build.venv\Scripts\python.exe -m pip install --upgrade pip
ERROR: No matching distribution found for pythonnet>=3.0.0
ERROR:builddrone.runner:Module failed: python.install
ERROR:builddrone.runner:python -m builddrone: error: Install failed with exit code 1
Command exited with code 1
$ErrorActionPreference = 'Continue'
& "$env:PYTHON\python.exe" -m builddrone appveyor_upload_failure_artifacts

https://ci.appveyor.com/project/GDATACyberDefenseAG/robotframework-flaui/builds/54547081/job/12jsv68pxuyc2e4w

[Houbein]

I openened a ticket there: pythonnet/pythonnet#2737