feat: add support for Kubernetes v1.19.8

[mboersma]

Reason for Change:

See https://github.com/kubernetes/kubernetes/blob/master/CHANGELOG/CHANGELOG-1.19.md#changelog-since-v1197

Issue Fixed:

Credit Where Due:

Does this change contain code from or inspired by another project?

• No
• Yes

Requirements:

• Kubernetes artifacts built and pushed by Azure Pipelines
• uses conventional commit messages
• includes documentation
• adds unit tests
• tested upgrade from previous version

Notes:

[codecov]

Codecov Report

Merging #4283 (fb6fcc6) into master (b9c9dda) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff           @@
##           master    #4283   +/-   ##
=======================================
  Coverage   72.06%   72.06%           
=======================================
  Files         141      141           
  Lines       21686    21686           
=======================================
  Hits        15628    15628           
  Misses       5107     5107           
  Partials      951      951           

Impacted Files	Coverage Δ
pkg/api/common/versions.go	96.37% <ø> (ø)

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[jackfrancis]

/lgtm

[acs-bot]

[APPROVALNOTIFIER] This PR is APPROVED

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