update compilesb3 snapshot test

Same as in #150.

Author: towerofnix

src/__tests__/__snapshots__/compilesb3.test.ts.snap

@@ -266,7 +266,7 @@ export default class Stage extends StageBase {
       "thing"
     );
     this.vars.testList.splice(
-      this.itemOf(this.vars.testList, 0) - 1,
+      this.toNumber(this.itemOf(this.vars.testList, 0)) - 1,
       1,
       this.vars.testList.length
     );