project: Explicit Python versions in metadata

Pypi allows for filtering on Python language versions, make these
explicit in the project.

Signed-off-by: Pieter De Gendt <[email protected]>

Author: pdgendt

pyproject.toml

@@ -8,7 +8,11 @@ version = "1.3.99"
 authors = [{name = "Zephyr Project", email = "[email protected]"}]
 description = "Zephyr RTOS Project meta-tool"
 classifiers = [
-    "Programming Language :: Python :: 3",
+    "Programming Language :: Python :: 3.9",
+    "Programming Language :: Python :: 3.10",
+    "Programming Language :: Python :: 3.11",
+    "Programming Language :: Python :: 3.12",
+    "Programming Language :: Python :: 3.13",
     "License :: OSI Approved :: Apache Software License",
     "Operating System :: POSIX :: Linux",
     "Operating System :: MacOS :: MacOS X",