fix: disable Sonarcloud for external PRs

[Justxd22]

Updated Sonarcloud so it does not run for fork PRs

Effect:

• push and internal PRs: SonarCloud still runs.
• PRs from external forks: SonarCloud job is skipped, so it won’t fail due to missing secrets.

Related Issue

#402

Types of changes

• Non-functional change (docs, style, minor refactor)
• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to change)

Checklist:

• My code follows the code style of this project.
• My change requires a change to the documentation.
• I have updated the documentation accordingly.
• I have read the CONTRIBUTING document.
• I have added tests to cover my code changes.
• All new and existing tests passed.

[cameri]

Thank you!!!