[FIX] tests: update tests error messages

Updating my node version to v16, I noticed many tests breaking, because
the way errors are formatted did change.  This commit ensures that the
test suite keeps working for all node versions.

tests/misc/portal.test.ts

@@ -546,7 +546,8 @@ describe("Portal: Basic use and DOM placement", () => {
       error = e;
     }
     expect(error).toBeDefined();
-    expect(error.message).toBe("Cannot read property 'crash' of undefined");
+    const regexp = /Cannot read properties of undefined \(reading 'crash'\)|Cannot read property 'crash' of undefined/g
+    expect(error.message).toMatch(regexp);
   });
 
   test("portal manual unmount", async () => {