Fix CI: add missing toast-forwarder to snapshot and add changesets

Signed-off-by: Patrik Oldsberg <poldsberg@gmail.com>
Made-with: Cursor

.changeset/deprecate-alert-api-core-app.md

@@ -0,0 +1,5 @@
+---
+'@backstage/core-app-api': patch
+---
+
+Deprecated `AlertApiForwarder` in favor of the new `ToastApi`. The `AlertApiForwarder` now emits a console warning on first use, guiding developers to migrate to `ToastApi` from `@backstage/frontend-plugin-api`.

.changeset/deprecate-alert-api-core-plugin.md

@@ -0,0 +1,5 @@
+---
+'@backstage/core-plugin-api': patch
+---
+
+Deprecated `AlertApi`, `AlertMessage`, and `alertApiRef` in favor of the new `ToastApi` from `@backstage/frontend-plugin-api`.

packages/frontend-defaults/src/createApp.test.tsx

@@ -357,6 +357,7 @@ describe('createApp', () => {
           <api:app/dialog out=[core.api.factory] />
           <api:app/discovery out=[core.api.factory] />
           <api:app/alert out=[core.api.factory] />
+          <api:app/toast-forwarder out=[core.api.factory] />
           <api:app/toast out=[core.api.factory] />
           <api:app/analytics out=[core.api.factory] />
           <api:app/error out=[core.api.factory] />