Merge branch 'python-3.12' into 'main'

meson.build: require python 3.10, try python3.12

See merge request mesa/mesa!40305

docs/install.rst

@@ -36,7 +36,7 @@ you're willing to maintain support for other compiler get in touch.
 Third party/extra tools.
 ^^^^^^^^^^^^^^^^^^^^^^^^
 
-- `Python <https://www.python.org/>`__ - Python 3.9 or newer is required.
+- `Python <https://www.python.org/>`__ - Python 3.10 or newer is required.
 - Python package ``packaging`` is required on Python 3.12+:
   ``pip install packaging``
 - `Python Mako module <https://www.makotemplates.org/>`__ - Python Mako

meson.build

@@ -1032,8 +1032,23 @@ if get_option('allow-kcmp') \
   pre_args += '-DALLOW_KCMP'
 endif
 
-# On Windows, a venv has no versioned aliased to 'python'.
-prog_python = find_program('python3', 'python', version : '>= 3.9')
+# Find a python executable that meets our version requirement.
+# - On Windows, a venv has no versioned aliased to 'python'.
+# - On RHEL 9, python3 is 3.9, so we must use python3.12.
+python_version_req = '>= 3.10'
+python_exec_list = ['python3.16', 'python3.15', 'python3.14', 'python3.13',
+                    'python3.12', 'python3.11', 'python3.10', 'python3', 'python']
+
+foreach p : python_exec_list
+  prog_python = find_program(p, required : false, version : python_version_req)
+  if prog_python.found()
+    break
+  endif
+endforeach
+
+if not prog_python.found()
+  error('Python ' + python_version_req + ' not found')
+endif
 
 has_mako = run_command(
   prog_python, '-c',