build: fix CI failures

Fixes a lint issue and a type error.

Author: crisbeto

src/app/pages/component-sidenav/component-sidenav.spec.ts

@@ -30,7 +30,7 @@ describe('ComponentSidenav', () => {
     waitForAsync(() => {
       expect(component.sidenav() instanceof MatSidenav).toBeTruthy();
       component.isScreenSmall.pipe(take(1)).subscribe(isSmall => expect(isSmall).toBeTruthy());
-      expect(component.sidenav().opened).toBe(false);
+      expect(component.sidenav()!.opened).toBe(false);
     });
   });
 

src/app/pages/component-sidenav/component-sidenav.ts

@@ -16,11 +16,7 @@ import {AsyncPipe} from '@angular/common';
 import {FormsModule} from '@angular/forms';
 import {MatIconModule} from '@angular/material/icon';
 import {MatListModule} from '@angular/material/list';
-import {
-  MatSidenav,
-  MatSidenavModule,
-  MatDrawerToggleResult,
-} from '@angular/material/sidenav';
+import {MatSidenav, MatSidenavModule} from '@angular/material/sidenav';
 import {
   ActivatedRoute,
   Params,