Add support to `pyparsing>=3.0.0`.
Changes required:
- `originalTextFor` -> `original_text_for`
- `stringEnd` -> `string_end`
- `stringStart` -> `string_start`

Update UT: `test_parseexception_error_msg` to check for `string_end`
instead of `stringEnd` in exception message.

Install current `packaging` and its dependencies during lint.
`nox` depends on `packaging`, by installing `nox` during lint phase,
`packaging` dependencies defined in working branch are overridden by
latest `packaging` release dependencies.
In this case, since the PR changes the constraints on `pyparsing`,
without a `session.install(".")` the incorrect `pyparsing` version will
be installed.

This ensures that we install the dependencies of current working branch
of `packaging`.
Similar to previous commit. `build` package depends on `packaging` and
installing it overrides the dependencies of current working branch by
the dependencies of latest `packaging` release.

See: https://github.com/pypa/packaging/pull/480/files#r740158146

As suggested by @layday, local `packaging` package directory takes
precedence over the installed `packaging`. By building with
`pyproject-build`, CWD will not be added to python path.