dist: Set default Linux target to manylinux2014

According to
https://github.com/mayeut/pep600_compliance/blob/master/README.rst
manylinux2010 is EOL, and so are all Linux distributions that support manylinux2010 but not manylinux2014.

Setting the default to manylinux2014 means that more thirdparty packages are supported and hopefully means we're not always behind and have to struggle to keep building for it.

direct/src/dist/commands.py

@@ -263,7 +263,7 @@ class build_apps(setuptools.Command):
         self.exclude_modules = {}
         self.icons = {}
         self.platforms = [
-            'manylinux2010_x86_64',
+            'manylinux2014_x86_64',
             'macosx_10_9_x86_64',
             'win_amd64',
         ]
@@ -588,7 +588,7 @@ class build_apps(setuptools.Command):
         if platform.startswith('linux_'):
             # Also accept manylinux.
             arch = platform[6:]
-            pip_args += ['--platform', 'manylinux2010_' + arch]
+            pip_args += ['--platform', 'manylinux2014_' + arch]
 
         if self.use_optimized_wheels:
             pip_args += [