perf(ivy): remove unused argument in hostBindings function (#34969)

We had some logic for generating and passing in the `elIndex` parameter into the `hostBindings` function, but it wasn't actually being used for anything. The only place left that had a reference to it was the `StylingBuilder` and it only stored it without referencing it again.

PR Close #34969

packages/core/test/render3/ivy/jit_spec.ts

@@ -233,7 +233,7 @@ ivyEnabled && describe('render3 jit', () => {
     const cmpDef = (Cmp as any).ɵcmp as ComponentDef<Cmp>;
 
     expect(cmpDef.hostBindings).toBeDefined();
-    expect(cmpDef.hostBindings !.length).toBe(3);
+    expect(cmpDef.hostBindings !.length).toBe(2);
   });
 
   it('should compile @Pipes without errors', () => {