more codeql suppressing (microsoft#185788)

microsoft/vscode-internalbacklog#4378

Author: jrieken

src/vs/workbench/api/common/extHostTypes.ts

@@ -1022,7 +1022,7 @@ export class SnippetString {
 			defaultValue = nested.value;
 
 		} else if (typeof defaultValue === 'string') {
-			defaultValue = defaultValue.replace(/\$|}/g, '\\$&');
+			defaultValue = defaultValue.replace(/\$|}/g, '\\$&'); // CodeQL [SM02383] I do not want to escape backslashes here
 		}
 
 		this.value += '${';