chore(deps): update github/codeql-action action to v2.21.0

[renovate[bot]]

This PR contains the following updates:

Package	Type	Update	Change	Pending
github/codeql-action	action	minor	v2.20.4 -> v2.21.0	v2.21.2 (+1)

Review

• [ ] Updates have been tested and work
• [ ] If updates are AWS related, versions match the infrastructure (e.g. Lambda runtime, database, etc.)

---

Release Notes

github/codeql-action (github/codeql-action)

### [`v2.21.0`](https://togithub.com/github/codeql-action/compare/v2.20.4...v2.21.0) [Compare Source](https://togithub.com/github/codeql-action/compare/v2.20.4...v2.21.0)

---

Configuration

📅 Schedule: Branch creation - "every weekend" in timezone America/Montreal, Automerge - At any time (no schedule defined).

🚦 Automerge: Disabled by config. Please merge this manually once you are satisfied.

♻ Rebasing: Whenever PR is behind base branch, or you tick the rebase/retry checkbox.

🔕 Ignore: Close this PR and you won't be reminded about this update again.

---

• [ ] If you want to rebase/retry this PR, check this box

---

This PR has been generated by Mend Renovate. View repository job log here.

[patheard]

• https://github.com/cds-snc/platform-core-services/issues/432