fix(auth): remove leading dot in auth cookie cleanup

Signed-off-by: Jessica He <jhe@redhat.com>

.changeset/clean-toys-reply.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-auth-node': patch
+---
+
+remove leading dot in auth cookie cleanup call

plugins/auth-node/src/oauth/OAuthCookieManager.ts

@@ -189,7 +189,7 @@ export class OAuthCookieManager {
       const { hostname: domain } = new URL(this.options.callbackUrl);
       output = output.cookie(name, '', {
         ...this.getRemoveCookieOptions(),
-        domain: `.${domain}`,
+        domain: domain,
       });
     }