Drop support for python < 3.10

It's time, there are nice features added by 3.8, 3.9, and 3.10. We're
also forced to pin mypy, meaning we don't get access to mypy and
typeshed fixes.

Author: dcbaker

docs/markdown/Release-notes-for-1.10.0.md

@@ -287,3 +287,9 @@ Previously, [[@custom_tgt]] were accepted but silently ignored, and
 
 Now, they both can be used, and the generated outputs will be scanned to extract
 translation strings.
+
+## Last major version supporting Python 3.7, 3.8, and 3.9
+
+Python older than 3.10 is now EOL, and Meson will drop support for these
+versions in the next major release, and will freely use features from 3.8, 3.9
+and 3.10. Support for these versions will remain for the 1.10.x series.

mesonbuild/mesonmain.py

@@ -187,7 +187,7 @@ def run(self, args: T.List[str]) -> int:
         # support for old python. If this is already the oldest supported version, then
         # this can never be true and does nothing.
         pending_python_deprecation_notice = \
-            command in {'setup', 'compile', 'test', 'install'} and sys.version_info < (3, 7)
+            command in {'setup', 'compile', 'test', 'install'} and sys.version_info < (3, 10)
 
         try:
             return options.run_func(options)
@@ -198,8 +198,8 @@ def run(self, args: T.List[str]) -> int:
                 mlog.warning('Running the setup command as `meson [options]` instead of '
                              '`meson setup [options]` is ambiguous and deprecated.', fatal=False)
             if pending_python_deprecation_notice:
-                mlog.notice('You are using Python 3.6 which is EOL. Starting with v0.62.0, '
-                            'Meson will require Python 3.7 or newer', fatal=False)
+                mlog.notice(f'You are using Python 3.{sys.version_info.minor} which is EOL. Starting with v1.11.0, '
+                            'Meson will require Python 3.10 or newer', fatal=False)
             mlog.shutdown()
 
 def run_script_command(script_name: str, script_args: T.List[str]) -> int: