test: fix a broken reporter test (#29514)

It failed to print an error with missing stack, e.g. a timeout error.

tests/playwright-test/test-step.spec.ts

@@ -47,8 +47,8 @@ class Reporter {
   distillError(error) {
     return {
       error: {
-        message: stripAnsi(error.message),
+        message: stripAnsi(error.message || ''),
-        stack: stripAnsi(error.stack),
+        stack: stripAnsi(error.stack || ''),
       }
     };
   }
@@ -351,6 +351,12 @@ test('should not report nested after hooks', async ({ runInlineTest }) => {
         },
       ],
     },
+    {
+      error: {
+        message: 'Test timeout of 2000ms exceeded.',
+        stack: ''
+      },
+    },
   ]);
 });
 
@@ -972,6 +978,18 @@ test('should not mark page.close as failed when page.click fails', async ({ runI
         },
       ],
     },
+    {
+      error: {
+        message: 'Test timeout of 2000ms exceeded.',
+        stack: '',
+      },
+    },
+    {
+      error: {
+        message: expect.stringContaining('Error: page.click'),
+        stack: expect.stringContaining('Error: page.click'),
+      },
+    },
   ]);
 });