Bump pyyaml from 5.3.1 to 6.0

Bumps pyyaml from 5.3.1 to 6.0.

Changelog

Sourced from pyyaml's changelog.

6.0 (2021-10-13)

• yaml/pyyaml#327 -- Change README format to Markdown
• yaml/pyyaml#483 -- Add a test for YAML 1.1 types
• yaml/pyyaml#497 -- fix float resolver to ignore . and ._
• yaml/pyyaml#550 -- drop Python 2.7
• yaml/pyyaml#553 -- Fix spelling of “hexadecimal”
• yaml/pyyaml#556 -- fix representation of Enum subclasses
• yaml/pyyaml#557 -- fix libyaml extension compiler warnings
• yaml/pyyaml#560 -- fix ResourceWarning on leaked file descriptors
• yaml/pyyaml#561 -- always require Loader arg to yaml.load()
• yaml/pyyaml#564 -- remove remaining direct distutils usage

5.4.1 (2021-01-20)

• yaml/pyyaml#480 -- Fix stub compat with older pyyaml versions that may unwittingly load it

5.4 (2021-01-19)

• yaml/pyyaml#407 -- Build modernization, remove distutils, fix metadata, build wheels, CI to GHA
• yaml/pyyaml#472 -- Fix for CVE-2020-14343, moves arbitrary python tags to UnsafeLoader
• yaml/pyyaml#441 -- Fix memory leak in implicit resolver setup
• yaml/pyyaml#392 -- Fix py2 copy support for timezone objects
• yaml/pyyaml#378 -- Fix compatibility with Jython

Commits

• 8cdff2c 6.0 release
• a4fb55e Update Python 3.10 versions for Windows build
• e45b964 Add Python 3.10 to tox.ini
• 4808fba 6.0b1 release
• d5aba40 Omnibus CI/artifact build update
• a6d384c Various setup fixes
• 8f3f979 No longer using appveyor
• c274365 The yaml.load{,_all} functions require Loader= now
• 2f87ac4 Add a basic test file for yaml.load and yaml.dump
• 7bd92df Makefile tweaks
• Additional commits viewable in compare view

---

Dependabot commands

You can trigger Dependabot actions by commenting on this MR

• $dependabot rebase will rebase this MR
• $dependabot recreate will recreate this MR rewriting all the manual changes and resolving conflicts