Backport of [NET-2420] security: add security scans on protected branches into release/1.1.x

[hc-github-team-consul-core]

Backport

This PR is auto-generated from #433 to be assessed for backporting due to the inclusion of the label backport/1.1.

🚨

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:
@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-dataplane/merges: 409 Merge conflict []

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

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Changes proposed in this PR

• Enable proactive triage by scanning PRs and merges to protected branches.
• Add exceptions to test and local tooling submodules to improve signal in security scans and simplify triage.
• Add docs and align config to [NET-2420] security: re-enable security scan release block consul-k8s#3628 (no functional changes) for easier maintenance.

See hashicorp/consul#19978 for similar changes in those repos, adapted here.

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Overview of commits

• add57af

[hashicorp-cla]

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