Update sbt export graph file name

What does this MR do?

This MR adds omission from v2.29.0 where the sbt parser was changed but the export graph file the finder package was searching for was not. This prevents sbt multi project build support.

What are the relevant issue numbers?

gitlab-org/gitlab#271345 (closed)

Does this MR meet the acceptance criteria?

• Changelog entry added
• Documentation created/updated for GitLab EE, if necessary
• Documentation created/updated for this project, if necessary
• Documentation reviewed by technical writer or follow-up review issue created
• Tests added for this feature/bug
• Job definition updated, if necessary
  • Auto-DevOps template
  • Job definition example
  • CI Templates
• Conforms to the code review guidelines
• Conforms to the Go guidelines
• Security reports checked/validated by reviewer