Bump packaging from 20.4 to 20.7

Bumps packaging from 20.4 to 20.7.

Changelog

Sourced from packaging's changelog.

20.7 - 2020-11-28

No unreleased changes.

20.6 - 2020-11-28

.. note:: This release was subsequently yanked, and these changes were included in 20.7.

• Fix flit configuration, to include LICENSE files (:issue:357)

20.5 - 2020-11-27

* Officially support Python 3.9 (:issue:`343`)
* Deprecate the ``LegacyVersion`` and ``LegacySpecifier`` classes (:issue:`321`)
* Handle ``OSError`` on non-dynamic executables when attempting to resolve
  the glibc version string.

Commits

• c048e34 Bump for release
• d26543a Merge remote-tracking branch 'upstream/master' into master
• 7cfbf62 Bump for development
• 07f0954 Bump for release
• 27ee84a Update changelog with unreleased changes
• 0e50236 Include licenses in sdist (#358)
• 55c3311 Bump for development
• 07b8ff4 Bump for release
• 08fe312 Reference the correct file in the release process
• 746aff4 add support for macos 11.0, arm64, universal2 (#319)
• Additional commits viewable in compare view