changefeedccl: fix reversed args for containment check in test logic

Fix a testing bug introduced in #131545 where the `Contains` check
arguments were reversed. The error string being _searched_ should
precede the string being _searched for_. The examples from the API docs:

```
//	require.Contains(t, "Hello World", "World")
//	require.Contains(t, ["Hello", "World"], "World")
//	require.Contains(t, {"Hello": "World"}, "Hello")
```

Release note: None

Author: nicktrav

pkg/ccl/changefeedccl/changefeedbase/errors_test.go

@@ -46,7 +46,7 @@ func TestAsTerminalError(t *testing.T) {
 	t.Run("node drain marked as job retry", func(t *testing.T) {
 		cause := errors.New("some error happened")
 		termErr := changefeedbase.AsTerminalError(context.Background(), nodeIsDraining, cause)
-		require.Contains(t, cause.Error(), termErr.Error())
+		require.Contains(t, termErr.Error(), cause.Error())
 		require.True(t, jobs.IsRetryJobError(termErr))
 	})
 
@@ -55,19 +55,19 @@ func TestAsTerminalError(t *testing.T) {
 		cause := changefeedbase.WithTerminalError(
 			changefeedbase.MarkRetryableError(errors.New("confusing error")))
 		termErr := changefeedbase.AsTerminalError(context.Background(), nodeIsNotDraining, cause)
-		require.Contains(t, cause.Error(), termErr.Error())
+		require.Contains(t, termErr.Error(), cause.Error())
 	})
 
 	t.Run("assertion failures are terminal", func(t *testing.T) {
 		// Assertion failures are terminal, even if marked as retry-able.
 		cause := changefeedbase.MarkRetryableError(errors.AssertionFailedf("though shall not pass"))
 		termErr := changefeedbase.AsTerminalError(context.Background(), nodeIsNotDraining, cause)
-		require.Contains(t, cause.Error(), termErr.Error())
+		require.Contains(t, termErr.Error(), cause.Error())
 	})
 
 	t.Run("gc error is terminal", func(t *testing.T) {
 		cause := changefeedbase.MarkRetryableError(&kvpb.BatchTimestampBeforeGCError{})
 		termErr := changefeedbase.AsTerminalError(context.Background(), nodeIsNotDraining, cause)
-		require.Contains(t, cause.Error(), termErr.Error())
+		require.Contains(t, termErr.Error(), cause.Error())
 	})
 }