Pex

This release fixes the computation of the hash of the code within a PEX
when nested within directories, a bug introduced in 2.1.149.

* Exclude pyc dirs, not include, when hashing code (2286)

This release brings support for a new `--exclude <req>` PEX build option
that allows eliding selected resolved distributions from the final PEX.
This is an advanced feature that will, in general, lead to broken PEXes
out of the box; so read up on the `--exclude` command line help to make
sure you understand the consequences.

This release also brings a fix for `--inject-env` that ensures the
specified environment variables are always injected to the PEX at
runtime regardless of the PEX entry point exercised.

* Implement support for `--exclude <req>`. (2281)
* Relocate environment variable injection to before the interpreter is run (2260)

This release brings support for `--pip-version 23.3.1`.

* Add support for Pip 23.3.1. (2276)

Fix `--style universal` lock handing of `none` ABI wheels with a
specific Python minor version expressed in their wheel tag. There are
not many of these in the wild, but a user discovered the case of
python-forge 18.6.0 which supplies 1 file on PyPI:
`python_forge-18.6.0-py35-none-any.whl`.

* Fix universal lock handling of the none ABI. (2270)

Add support to the Pex for checking if built PEXes are valid Python
zipapps. Currently, Python zipapps must reside in 32 bit zip files due
to limitations of the stdlib `zipimport` module's `zipimporter`; so this
check amounts to a check that the built PEX zip does not use ZIP64
extensions. The check is controlled with a new
`--check {none,warn,error}` option, defaulting to warn.

* Add --check support for zipapps. (2253)

Add support for `--use-pip-config` to allow the Pip Pex calls to read
`PIP_*` env vars and Pip configuration files. This can be particularly
useful for picking up custom index configuration (including auth).

* Add support for --use-pip-config. (2243)