fix(saml-auth): Add default option for getBackstageIdentity

Signed-off-by: Joel Low <joel@joelsplace.sg>

.changeset/shy-vans-return.md

@@ -0,0 +1,5 @@
+---
+'@backstage/core-api': patch
+---
+
+Fix error when querying Backstage Identity with SAML authentication

packages/core-api/src/apis/implementations/auth/saml/SamlAuth.ts

@@ -83,7 +83,7 @@ class SamlAuth implements ProfileInfoApi, BackstageIdentityApi, SessionApi {
   }
 
   async getBackstageIdentity(
-    options: AuthRequestOptions,
+    options: AuthRequestOptions = {},
   ): Promise<BackstageIdentity | undefined> {
     const session = await this.sessionManager.getSession(options);
     return session?.backstageIdentity;