v0.15.0

Added:

• Update default distributions to 20240224
• Update default Python version to 3.12
• Statically link the C runtime on Windows
• Add PYAPP_PROJECT_FEATURES option for selecting extras
• Add new execution mode option PYAPP_EXEC_NOTEBOOK for running Jupyter notebooks

Fixed:

• Properly resolve correct default distributions on MinGW-w64
• Fix embedding custom distributions
• Ignore nonexistent variant options for 3.7 distributions