Handle auth for claude (#36442)

We'll now use the anthropic provider to get credentials for `claude` and
embed its configuration view in the panel when they are not present.

Release Notes:

- N/A

crates/ai_onboarding/src/agent_api_keys_onboarding.rs

@@ -11,7 +11,7 @@ impl ApiKeysWithProviders {
         cx.subscribe(
             &LanguageModelRegistry::global(cx),
             |this: &mut Self, _registry, event: &language_model::Event, cx| match event {
-                language_model::Event::ProviderStateChanged
+                language_model::Event::ProviderStateChanged(_)
                 | language_model::Event::AddedProvider(_)
                 | language_model::Event::RemovedProvider(_) => {
                     this.configured_providers = Self::compute_configured_providers(cx)