Fix race condition in paths.get_ipython_dirs(),

Directory may already exists.

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Merge remote-tracking branches 'origin/pull/13256' and 'origin/pull/13263'

IPython/paths.py

@@ -72,7 +72,7 b' def get_ipython_dir() -> str:'
                     " using a temp directory.".format(parent))
             ipdir = tempfile.mkdtemp()
         else:
-            os.makedirs(ipdir)
+            os.makedirs(ipdir, exist_ok=True)
     assert isinstance(ipdir, str), "all path manipulation should be str(unicode), but are not."
     return ipdir