Fix build and delete superfluous files

- Make Python make formatting pristine
- Add missing `#pragma weak` to Python source
- Fix Clang script flake due to missing directory

third_party/python/Python/sigcheck.c

@@ -1,3 +1,4 @@
+/* clang-format off */
 
 /* Sigcheck is similar to intrcheck() but sets an exception when an
    interrupt occurs.  It can't be in the intrcheck.c file since that
@@ -8,6 +9,8 @@
 
 #include "Python.h"
 
+#pragma weak PyErr_CheckSignals
+
 /* ARGSUSED */
 int
 PyErr_CheckSignals(void)