chore: bump version to 0.17.0

Python 3.10 is now required (minimum supported version raised), hence a
new minor version, which also gathers the fixes for #113 and #115.

- qwt/__init__.py: __version__ = "0.17.0".
- CHANGELOG.md: "Unreleased" section renamed to "Version 0.17.0".

Refs #115

Assisted-by: Claude Opus 5.5

Author: PierreRaybaut

CHANGELOG.md

@@ -1,6 +1,6 @@
 # PythonQwt Releases
 
-## Unreleased
+## Version 0.17.0
 
 ### Requirements
 

qwt/__init__.py

@@ -63,7 +63,7 @@
 from qwt.text import QwtText  # noqa: F401
 from qwt.toqimage import array_to_qimage as toQImage  # noqa: F401
 
-__version__ = "0.16.3"
+__version__ = "0.17.0"
 QWT_VERSION_STR = "6.1.5"