Backport of [NET-4103] ci: build s390x into release/1.15.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #18067 to be assessed for backporting due to the inclusion of the label backport/1.15.

🚨

Warning automatic cherry-pick of commits failed. If the first commit failed,
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The person who merged in the original PR is:
@loshz
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/merges: 409 Merge conflict []

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

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Description

This PR adds build and unit test support for the s390x architecture in Consul Enterprise automated workflows.

The following changes have been made:

• Build the Consul binary for s390x.
• Run tests using a dev build of the above binary.

Tested in ENT: https://github.com/hashicorp/consul-enterprise/pull/6265

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Overview of commits

• ae206e6 - fba313c - ef8acf1 - b9c673f - 8e0d911 - 5f0cc11 - a841123 - 85342d5 - 001c7c4 - 5483723 - 6ad6fbd - ab615ec - deed01d

[hashicorp-cla]

All committers have signed the CLA.

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

Auto approved Consul Bot automated PR