Revert "[Feature] Secondary fallback for package signature verification (#3453) (#3497)

[pchila]

This reverts commit 635b147.

What does this PR do?

Reverts commit that broke the ability of the agent to communicate locally with fleet-server when bootstrapping it.

Why is it important?

Restores Elastic cloud deployment functionality

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/fragments using the changelog tool
• I have added an integration test or an E2E test

Author's Checklist

• [ ]

How to test this PR locally

Related issues

• Closes Broken/Flaky integration tests on main #3502

Use cases

Screenshots

Logs

Questions to ask yourself

• How are we going to support this in production?
• How are we going to measure its adoption?
• How are we going to debug this?
• What are the metrics I should take care of?
• ...

[elasticmachine]

Pinging @elastic/elastic-agent-control-plane (Team:Elastic-Agent-Control-Plane)

[elasticmachine]

💚 Build Succeeded

the below badges are clickable and redirect to their specific view in the CI or DOCS

Expand to view the summary

Build stats

• Start Time: 2023-10-04T11:50:13.022+0000

• Duration: 28 min 51 sec

Test stats 🧪

Test	Results
Failed	0
Passed	6277
Skipped	55
Total	6332

💚 Flaky test report

Tests succeeded.

🤖 GitHub comments

Expand to view the GitHub comments

To re-run your PR in the CI, just comment with:

• /test : Re-trigger the build.

• /package : Generate the packages.

• run integration tests : Run the Elastic Agent Integration tests.

• run end-to-end tests : Generate the packages and run the E2E Tests.

• run elasticsearch-ci/docs : Re-trigger the docs validation. (use unformatted text in the comment!)

[elasticmachine]

🌐 Coverage report

Name	Metrics % (covered/total)	Diff
Packages	98.765% (80/81)	👍
Files	67.832% (194/286)	👎 -0.35
Classes	66.48% (357/537)	👍
Methods	53.112% (1118/2105)	👎 -0.117
Lines	38.563% (12702/32938)	👎 -0.102
Conditionals	100.0% (0/0)	💚

[cmacknz]

Force merging, we need this fix for the tests to pass.