Describe the bug
max and other aggregations are missing some overloads, like any has

To Reproduce

df = pd.DataFrame({'a': [1,2,3], 'b': [4,5,6]})
print(df.max(axis=None))

The stubs say this always returns Series, but actually, for axis=None, it returns a scalar

Please complete the following information:

• OS: [e.g. Windows, Linux, MacOS]
• OS Version [e.g. 22]
• python version
• version of type checker
• version of installed pandas-stubs

Additional context
Add any other context about the problem here.