SASTBot: Monthly dependency updates for 15.10

What does this MR do?

• upgrade github.com/stretchr/testify version [v1.8.1 => v1.8.2]
• upgrade github.com/urfave/cli/v2 version [v2.24.3 => v2.25.0]
• upgrade gitlab.com/gitlab-org/security-products/analyzers/ruleset version [v1.4.0 => v1.4.1]

Note: Changelog is autogenerated by SASTBot.

What are the relevant issue numbers?

• 15.10 Planning — Static Analysis (gitlab-org/gitlab#392436 - 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