Pipx

- Fix infinite recursion error when installing package such as `cloudtoken==0.1.84` (103)
- Fix windows type errors (96, 98)

- Fix "WindowsPath is not iterable" bug

- Add `--include-deps` argument to include binaries of dependent packages when installing with pipx. This improves
compatibility with packages that depend on other installed packages, such as `jupyter`.
- Speed up `pipx list` output (by running multiple processes in parallel) and by collecting all metadata in a single
subprocess call
- More aggressive cache directory removal when `--no-cache` is passed to `pipx run`
- [dev] Move inline text passed to subprocess calls to their own files to enable autoformatting, linting, unit testing

- Add support for PEP 582's `__pypackages__` (experimental). `pipx run BINARY` will first search in `__pypackages__` for
binary, then fallback to installing from PyPI. `pipx run --pypackages BINARY` will raise an error if the binary is not
found in `__pypackages__`.
- Fix regression when installing with `--editable` flag (93)
- [dev] improve unit tests

- Cache and reuse temporary Virtual Environments created with `pipx run` (61)
- Update binary discovery logic to find "scripts" like awscli (91)
- Forward `--pip-args` to the pip upgrade command (previously the args were forwarded to install/upgrade commands for
packages) (77)
- When using environment variable PIPX_HOME, Virtual Environments will now be created at `$PIPX_HOME/venvs` rather than
at `$PIPX_HOME`.
- [dev] refactor into multiple files, add more unit tests

- Fix parsing bug in pipx run