fix install prevention on Linux

[intxgo]

What does this PR do?

go-sysinfo determines native architecture based on /proc filesystem which could be disabled, therefore the prevention should err on allowing installation when native architecture is unknown.

The fixed prevention was not included in any released version yet.

Why is it important?

Agent prevents adding Elastic Defend when it cannot determine if it's being emulated. However it's fine to install Elastic Defend in such case, as it does emulation check on it's own upon installation returning installation error when appropriate.

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

Related issues

• Relates fix linux kernel version string parsing when derermining kernel host architecture go-sysinfo#252

[mergify]

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

• backport-./d./d is the label that automatically backports to the 8./d branch. /d is the digit
• backport-active-all is the label that automatically backports to all active branches.
• backport-active-8 is the label that automatically backports to all active minor branches for the 8 major.
• backport-active-9 is the label that automatically backports to all active minor branches for the 9 major.

[elasticmachine]

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

[intxgo]

/test

comment from Panos needs to be addressed

[intxgo]

/test

[elastic-sonarqube]

Quality Gate passed

Issues
0 New issues
0 Fixed issues
0 Accepted issues

Measures
0 Security Hotspots
No data about Coverage
No data about Duplication

See analysis details on SonarQube

[pkoutsovasilis]

code changes look good to me. Waiting for the CI to complete just to strengthen my understanding of specs/endpoint-security.spec.yml that we are not breaking any IT (integration tests)