Fix security issues with build pods.

The build pod configurations added for the build scripts were just very basic. SonarCloud is warning that the configuration has some security issues, which causes the quality gate to fail: https://sonarcloud.io/project/issues?impactSoftwareQualities=SECURITY&resolved=false&severities=BLOCKER%2CCRITICAL%2CMAJOR%2CMINOR&sinceLeakPeriod=true&types=VULNERABILITY&id=cern-cta_CTA This should be fixed.