[Misc] Apply SonarCloud rule cpp:S998

Description

• Rule name: The name "main" should not be used for any function other than the global "main" function
• Rule code: cpp:S998
• Rule link: https://sonarcloud.io/organizations/cern-cta/rules?open=cpp%3AS998&rule_key=cpp%3AS998

Checklist

• Documentation reflects the changes made.
• Merge Request title is clear, concise, and suitable as a changelog entry. See our contributing docs

References

Closes #1382 (closed)