fix(cdk/tree): fix lint errors

Author: BobobUnicorn

src/cdk/tree/tree.spec.ts

@@ -1463,7 +1463,7 @@ describe('CdkTree', () => {
       .toBe(1);
   });
 
-  fit('statically renders nested children', () => {
+  it('statically renders nested children', () => {
     configureCdkTreeTestingModule([NestedChildrenExpansionTest]);
     const fixture = TestBed.createComponent(NestedChildrenExpansionTest);
     fixture.detectChanges();

src/cdk/tree/tree.ts

@@ -43,7 +43,6 @@ import {
   TrackByFunction,
   signal,
   effect,
-  untracked,
   ViewChild,
   ViewContainerRef,
   ViewEncapsulation,