[8.17](backport #44259) bk: use GCP OIDC

[mergify]

Proposed commit message

Use GPC OIDC to fetch the artifacts for building the npcap.
Use the new Google Storage which it's under the terraform configuration.

Checklist

• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• I have made corresponding change to the default configuration files
• I have added tests that prove my fix is effective or that my feature works
• I have added an entry in CHANGELOG.next.asciidoc or CHANGELOG-developer.next.asciidoc.

Disruptive User Impact

Author's Checklist

• [ ]

How to test this PR locally

In the CI.

I created a test PR for validating the changes in isolation:

• https://buildkite.com/elastic/beats-xpack-packetbeat/builds/14252

Related issues

Requires elastic/oblt-google-auth-buildkite-plugin#6

Use cases

Screenshots

Logs

---

This is an automatic backport of pull request #44259 done by [Mergify](https://mergify.com).

[mergify]

Cherry-pick of 3eec2b6 has failed:

On branch mergify/bp/8.17/pr-44259
Your branch is up to date with 'origin/8.17'.

You are currently cherry-picking commit 3eec2b65a.
  (fix conflicts and run "git cherry-pick --continue")
  (use "git cherry-pick --skip" to skip this patch)
  (use "git cherry-pick --abort" to cancel the cherry-pick operation)

Changes to be committed:
	deleted:    .buildkite/scripts/gcp_auth.ps1
	modified:   .buildkite/x-pack/pipeline.xpack.agentbeat.yml
	modified:   x-pack/packetbeat/scripts/mage/pcap.go

Unmerged paths:
  (use "git add <file>..." to mark resolution)
	both modified:   .buildkite/x-pack/pipeline.xpack.packetbeat.yml

To fix up this pull request, you can check it out locally. See documentation: https://docs.github.com/en/pull-requests/collaborating-with-pull-requests/reviewing-changes-in-pull-requests/checking-out-pull-requests-locally

[botelastic]

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