fix(callbacks): display all defined callbacks (#9223)

Refs #9222

test/e2e-cypress/e2e/features/oas3-callbacks.cy.js

@@ -0,0 +1,19 @@
+/**
+ * Related to // https://github.com/swagger-api/swagger-ui/issues/9222.
+ */
+
+describe("OpenAPI 3.0 Callbacks", () => {
+  it("should render all defined callbacks", () => {
+    cy.visit(
+      "/?url=/documents/features/oas3-callbacks.yaml"
+    )
+      .get("#operations-Device-register")
+      .click()
+      .get(".opblock-section-header .tab-item.false")
+      .click()
+      .get("#operations-callbacks-callbackOne")
+      .should("be.visible")
+      .get("#operations-callbacks-callbackTwo")
+      .should("be.visible")
+  })
+})