Backport of [NET-4904] Update list of Envoy versions in docs into release/1.15.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #18306 to be assessed for backporting due to the inclusion of the label backport/1.15.

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@zalimeni
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The below text is copied from the body of the original PR.

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Update supported Envoy versions across Consul release versions.

Note: it looks like these have fallen a bit out of date, so I'm expecting this to bring things up to speed in main and release/* branches.

Once we release 1.17, this will need to be updated again.

PRs to bump versions:

• [NET-4904] Update list of Envoy versions on 1.16.x #18303
• [NET-4904] Update list of Envoy versions on 1.15.x #18304
• [NET-4904] Update list of Envoy versions on 1.14.x #18305

PR Checklist

• updated test coverage
• external facing docs updated
• appropriate backport labels added
• not a security concern

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Overview of commits

• aaeaffd

[hashicorp-cla]

All committers have signed the CLA.

[github-team-consul-core-pr-approver]

Auto approved Consul Bot automated PR