GitHub workflow: Add Python versions

Author: andreArtelt

.github/workflows/build_test.yml

@@ -9,6 +9,7 @@ jobs:
     strategy:
       matrix:
         os: [ubuntu-latest, windows-latest, macos-15-intel, macos-latest]
+        python-version: ["3.10", "3.11", "3.12", "3.13", "3.14"]
         include:
           - os: macos-15-intel
             c_compiler: gcc-15