python,python3: remove multi-arch support, and /usr/local paths

This should hopefully reduce weird behaviour caused
by the host system.

Signed-off-by: Alexandru Ardelean <ardeleanalex@gmail.com>

lang/python/python3/patches/006-remove-multi-arch-and-local-paths.patch

@@ -0,0 +1,21 @@
+diff --git a/setup.py b/setup.py
+index f04bf22..01b851e 100644
+--- a/setup.py
++++ b/setup.py
+@@ -487,16 +487,9 @@ class PyBuildExt(build_ext):
+             return ['m']
+ 
+     def detect_modules(self):
+-        # Ensure that /usr/local is always used, but the local build
+-        # directories (i.e. '.' and 'Include') must be first.  See issue
+-        # 10520.
+-        if not cross_compiling:
+-            add_dir_to_list(self.compiler.library_dirs, '/usr/local/lib')
+-            add_dir_to_list(self.compiler.include_dirs, '/usr/local/include')
+         # only change this for cross builds for 3.3, issues on Mageia
+         if cross_compiling:
+             self.add_gcc_paths()
+-        self.add_multiarch_paths()
+ 
+         # Add paths specified in the environment variables LDFLAGS and
+         # CPPFLAGS for header and library files.