Set checkPresence in diff-range data extension

This commit updates the diff-range data extension to use the new
checkPresence field being introduced in CodeQL CLI 2.21.0, so that
diff-informed analysis no longer fails when a query pack does not have
the restrictAlertsTo extensible predicate.

src/analyze.ts

@@ -517,6 +517,7 @@ extensions:
   - addsTo:
       pack: codeql/util
       extensible: restrictAlertsTo
+      checkPresence: false
     data:
 `;