chore(deps): update docker.io/envoyproxy/envoy docker tag to v1.20.0

[renovate]

This PR contains the following updates:

Package	Update	Change
docker.io/envoyproxy/envoy	minor	v1.19.0 -> v1.20.0

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[github-actions]

Mega-Linter status: ✅ SUCCESS

Descriptor	Linter	Files	Fixed	Errors	Elapsed time
✅ EDITORCONFIG	editorconfig-checker	1		0	0.78s
✅ GIT	git_diff	yes		no	0.01s
✅ YAML	prettier	1	0	0	1.22s
✅ YAML	v8r	1		0	1.33s
✅ YAML	yamllint	1		0	0.11s

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[codecov]

Codecov Report

Merging #239 (b7b9093) into develop (a200954) will not change coverage.
The diff coverage is n/a.

@@           Coverage Diff            @@
##           develop     #239   +/-   ##
========================================
  Coverage    90.82%   90.82%           
========================================
  Files           96       96           
  Lines         1548     1548           
  Branches       269      269           
========================================
  Hits          1406     1406           
  Misses         142      142           

Flag	Coverage Δ
cypress	64.43% <ø> (ø)
jest	74.39% <ø> (ø)

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[pro-wh]

release notes https://www.envoyproxy.io/docs/envoy/v1.20.0/version_history/current sound fine

this first round is larger because we haven't been doing these, so I'll let this collect comments for one more day and merge tomorrow

[pro-wh]

on second thought, gonna merge along with #240