pyoxidizer: make sure defaultrc directory exists before trying to write to it

When doing some work involving one-file binaries, this line is failing
for me. It seems reasonable to just make sure the destination
directory exists before splatting the file into it.

Differential Revision: https://phab.mercurial-scm.org/D9401

contrib/packaging/hgpackaging/pyoxidizer.py

@@ -127,6 +127,7 b' def run_pyoxidizer('
 
         # Write out a default editor.rc file to configure notepad as the
         # default editor.
+        os.makedirs(out_dir / "defaultrc", exist_ok=True)
         with (out_dir / "defaultrc" / "editor.rc").open(
             "w", encoding="utf-8"
         ) as fh: