Ast-decompiler

- Support Python 3.12 and 3.13; stop testing Python 3.6 and 3.7
- Fix all DeprecationWarnings in the codebase

- Stop adding redundant parentheses to `complex` numbers with no real part and a negative
imaginary part (thanks to Alex Waygood)

- Support Python 3.11
- Fix bug where annotations on `*args` and `**kwargs` were dropped
- Stop adding redundant parentheses to tuple subscripts on Python 3.8 and lower
(thanks to Alex Waygood)

- Add `py.typed`
- Fix decompilation of f-strings containing escaped braces
- Preserve literal newlines in docstrings
- Fix decompilation of complex infinity
- Add support for Python 3.10 pattern matching
- Fix incorrect decompilation of lambdas in comprehension guards on Python 3.9 and higher
- Fix decompilation for dict `**` unpacking
- Modernize CI and packaging setup
- Fix tests under Python 3.9
- Add explicit LICENSE file

- Support Python 3.7 and 3.8 (thanks to Luke Plant)
- Allow keyword-only arguments without default values (thanks to Shantanu Jain)

- More f-string fixes (thanks to Shantanu Jain)