Add handling for bad data in ci_build options

What does this MR do?

There’s a scenario by which a stringified ruby hash is making it into options values, which can’t be serialized/deserialized properly but is currently not being handled. This fix resolves the scenarios we’re seeing where the data is invalid, but we should take steps to not allow that bad data into the system at all.

#34860 (closed) gitlab-com/gl-infra/production#1275 (closed)

Does this MR meet the acceptance criteria?

Conformity

• [-] Changelog entry
• [-] Documentation created/updated or follow-up review issue created
• Code review guidelines
• Merge request performance guidelines
• Style guides
• [-] Database guides
• [-] Separation of EE specific content

Availability and Testing

• Review and add/update tests for this feature/bug. Consider all test levels. See the Test Planning Process.
• [-] Tested in all supported browsers

~backstage ~bug