Update github/codeql-action action to v2.1.8

Editor assessment

`build: update github/codeql-action action to v2.1.8` is a fully self-sufficient CI-action bump: the exact action and target version are named, so the change is completely understandable without a diff. The absent body is appropriate for routine action maintenance, which the rubric exempts for small changes. The `PR Close #45542` footer is well formed and is the only trailer present. Style hygiene is excellent — imperative verb, no trailing period, compact subject, no ticket junk, consistent language. Teaching value is structurally minimal because there is nothing to explain, but the message is clear, correct, and honest, fully meeting the good bar.