Don't strip "v" from Go versions

What does this MR do?

Update go support to not strip "v" from versions when generating vulnerability and dependency report (to match convention).

What are the relevant issue numbers?

gitlab-org/gitlab#196520 (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 updated for this feature/bug. See gitlab-org/security-products/tests/go-modules!11 (diffs)
• [-] Job definition updated, if necessary
• Conforms to the code review guidelines
• Conforms to the Go guidelines
• Security reports checked/validated by reviewer