Bump minimum CodeQL Bundle version to 2.12.6

Author: henrymercer

lib/codeql.js

@@ -275,7 +275,7 @@ let cachedCodeQL: CodeQL | undefined = undefined;
  * The version flags below can be used to conditionally enable certain features
  * on versions newer than this.
  */
-const CODEQL_MINIMUM_VERSION = "2.11.6";
+const CODEQL_MINIMUM_VERSION = "2.12.6";
 
 /**
  * This version will shortly become the oldest version of CodeQL that the Action will run with.