fix(json-schema-2020-12): avoid accessing properties of null schemas (#10397)

test/e2e-cypress/e2e/features/plugins/json-schema-2020-12/empty-schema.cy.js

@@ -0,0 +1,12 @@
+/**
+ * @prettier
+ */
+
+describe("Empty JSON Schema 2020-12", () => {
+  it("should render as schema of type `any`", () => {
+    cy.visit("/?url=/documents/features/json-schema-2020-12-empty-schema.yaml")
+
+    cy.get(".json-schema-2020-12__title").should("contain", "Test")
+    cy.get(".json-schema-2020-12__attribute").should("contain", "any")
+  })
+})

test/e2e-cypress/static/documents/features/json-schema-2020-12-empty-schema.yaml

@@ -0,0 +1,4 @@
+openapi: 3.1.0
+components:
+  schemas:
+    Test: