fix(devtools): last supported version

Bump to 12, as the message suggests.

Author: hawkgs

devtools/projects/ng-devtools/src/lib/devtools.component.html

@@ -14,7 +14,8 @@
           <div class="devtools-state-screen">
             <mat-icon>upgrade</mat-icon>
             <p class="text-message">
-              Angular DevTools only supports Angular versions 12 and above.
+              Angular DevTools only supports Angular versions {{ LAST_SUPPORTED_VERSION }} and
+              above.
             </p>
           </div>
         }

devtools/projects/ng-devtools/src/lib/devtools.component.ts

@@ -47,7 +47,7 @@ enum AngularStatus {
   EXISTS,
 }
 
-export const LAST_SUPPORTED_VERSION = 9;
+export const LAST_SUPPORTED_VERSION = 12;
 
 @Component({
   selector: 'ng-devtools',
@@ -66,6 +66,8 @@ export class DevToolsComponent implements OnDestroy {
   readonly hydration = signal(false);
   readonly ivy = signal<boolean | undefined>(undefined);
 
+  readonly LAST_SUPPORTED_VERSION = LAST_SUPPORTED_VERSION;
+
   readonly supportedVersion = computed(() => {
     const version = this.angularVersion();
     if (!version) {