Backport of [NET-4865] security: Upgrade Go and net/http CVE-2023-29406 into release/1.0.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #2642 to be assessed for backporting due to the inclusion of the label backport/1.0.x.

🚨

Warning automatic cherry-pick of commits failed. If the first commit failed,
you will see a blank no-op commit below. If at least one commit succeeded, you
will see the cherry-picked commits up to, not including, the commit where
the merge conflict occurred.

The person who merged in the original PR is:
@zalimeni
This person should manually cherry-pick the original PR into a new backport PR,
and close this one when the manual backport PR is merged in.

merge conflict error: POST https://api.github.com/repos/hashicorp/consul-k8s/merges: 409 Merge conflict []

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

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Upgrade to Go 1.20.6 and net/http 1.12.0 to resolve CVE-2023-29406.

How I've tested this PR: tests continue to pass

How I expect reviewers to test this PR: 👀

Checklist:

• Tests added
• CHANGELOG entry added

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Overview of commits

• bab65ac

[hashicorp-cla]

All committers have signed the CLA.

[zalimeni]

Opening new PR to keep targeting Go 1.19, since that version was also patched and the 1.20 upgrade is not strictly necessary here.