Fix typo in .ignore file and rectify ignore rule logic in tests

This commit addresses the issue where the test logic wrongfully inverted the ignore rule condition:

1. A file naming typo (`003.ignroe` corrected to `003.ignore`) has been fixed, ensuring `.ignore` files are now properly recognized. Previously, the misnamed file caused certain test cases to be compared against expected outputs when they should have been ignored.

2. The test logic within `formatter_test.go` that determined whether to ignore discrepancies based on `.ignore` file presence was inverted. Before the fix, the presence of an `.ignore` file led to a test error upon output mismatch, while its absence merely logged the difference without failing the test. The corrected logic now reflects the intended behavior: when an `.ignore` file is present, the differing outputs are logged for review rather than causing the test to fail.

internal/formatter/formatter_test.go

@@ -156,7 +156,7 @@ func TestFormat(t *testing.T) {
 		}
 		want := string(b)
 		if got != want {
-			if _, err := os.Stat(fname[:len(fname)-4] + ".ignore"); err != nil {
+			if _, err := os.Stat(fname[:len(fname)-4] + ".ignore"); err == nil {
 				t.Logf("%s:\n"+
 					"    want: %q\n"+
 					"     got: %q\n",