Fix misc. comment typos

Found via `codespell`

IPython/core/magics/execution.py

@@ -507,7 +507,7 python-profiler package from non-free.""")
         *two* back slashes (e.g. ``\\\\*``) to suppress expansions.
         To completely disable these expansions, you can use -G flag.
 
-        On Windows systems, the use of single quotes `'` when specifing 
+        On Windows systems, the use of single quotes `'` when specifying 
         a file is not supported. Use double quotes `"`.
 
         Options:

IPython/core/tests/test_inputtransformer2.py

@@ -225,7 +225,7 def test_transform_help():
 
 def test_find_assign_op_dedent():
     """
-    be carefull that empty token like dedent are not counted as parens
+    be careful that empty token like dedent are not counted as parens
     """
     class Tk:
         def __init__(self, s):