This was asked about in #9298 and the issue log stated "closed as not planned". The "answer" was to dismiss via the UI. But this alone is really not a sufficient mechanism:

• Having to interact with the UI is supremely annoying
• Spurious new warnings if the code moves cannot be avoided this way
• It is good to be forced to comment these exception inline where they happen
• What if you are running codeql locally? Then here is no mechanisim?

Please consider supporting this basic, table-stakes feature that many, many linting/scanning tools afford.