FIPS Build

[michel-laterman]

What does this PR do?

Adds FIPS env var to magefile to enable FIPS compliant builds using the microsoft/go toolchain.

This PR will not be sufficient to ensure that every artifact made with these changes are compliant, we still need to verify our crypto use.

Why is it important?

FIPS artifacts must be built with compliant toolchains.

Checklist

• I have read and understood the pull request guidelines of this project.
• 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

Disruptive User Impact

None

How to test this PR locally

Assuming microsoft go is available, run FIPS=true mage build:binary

[mergify]

This pull request does not have a backport label. Could you fix it @michel-laterman? 🙏
To fixup this pull request, you need to add the backport labels for the needed
branches, such as:

• backport-./d./d is the label to automatically backport to the 8./d branch. /d is the digit

[mergify]

backport-v8.x has been added to help with the transition to the new branch 8.x.
If you don't need it please use backport-skip label and remove the backport-8.x label.

[elasticmachine]

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

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

See analysis details on SonarQube

[cmacknz]

This should come with a test that the binary we produce actually works, ideally one that can confirm it properly uses the FIPS OpenSSL in the expected way.

You'll also need to update CI to actually build the FIPS variant, the package steps for testing are in

elastic-agent/.buildkite/integration.pipeline.yml

Line 8 in a29af64

- group: "Integration tests: packaging"

right now