refactor(pypi): A better error message when the wheel select hits no_match

[aignas]

With this change we get the current values of the python configuration
values printed in addition to the message printed previously. This
should help us advise users who don't have their builds configured
correctly.

We are adding an extra build_setting which we can set in order to get
an error message instead of a DEBUG warning. This has been documented
as part of our config settings and in the no_match_error in the
select statement.

Example output now

$ bazel cquery --@rules_python//python/config_settings:python_version=3.12 @dev_pip//sphinx
DEBUG: /home/aignas/src/github/aignas/rules_python/python/private/config_settings.bzl:200:14: The current build configuration's rules_python flag values are:
    @@//python/config_settings:pip_whl: "auto"
    @@//python/config_settings:pip_whl_glibc_version: ""
    @@//python/config_settings:pip_whl_muslc_version: ""
    @@//python/config_settings:pip_whl_osx_arch: "arch"
    @@//python/config_settings:pip_whl_osx_version: ""
    @@//python/config_settings:py_freethreaded: "no"
    @@//python/config_settings:py_linux_libc: "glibc"
    @@//python/config_settings:python_version: "3.12"

See documentation:
https://rules-python.readthedocs.io/en/latest/api/rules_python/python/config_settings
ERROR: /home/aignas/.cache/bazel/_bazel_aignas/6f0de8c9128ee8d5dbf27ba6dcc48bdd/external/+pip+dev_pip/sphinx/BUILD.bazel:6:12: configurable attribute "actual" in @@+pip+dev_pip//sphinx:_no_match_error doesn't match this configuration: No matching wheel for current configuration's Python version.

The current build configuration's settings do not match any of the Python wheels available for this distribution. This distribution supports the following configuration settings:
    //_config:is_cp3.11_py3_none_any
    //_config:is_cp3.13_py3_none_any

To determine the current build configuration flag values, see the debug message above or re-run the build with:
    --@@//python/config_settings:current_config=fail

For other configuration, run:
    `bazel config <config id>` (shown further below)

This instance of @@+pip+dev_pip//sphinx:_no_match_error has configuration identifier 29ffcf8. To inspect its configuration, run: bazel config 29ffcf8.

For more help, see https://bazel.build/docs/configurable-attributes#faq-select-choose-condition.

ERROR: Analysis of target '@@+pip+dev_pip//sphinx:sphinx' failed; build aborted: Analysis failed
INFO: Elapsed time: 0.100s
INFO: 0 processes.
ERROR: Build did NOT complete successfully

Fixes #2466

[rickeylev]

LGTM after the discussed changes (add manual tag, revert python_version_flag being public)