progress: update TestRunOSBuildWithProgressIncorrectJSON

The error message of the images library about incorrect
json is more "correct" now by including the trailing \n.

This is because of osbuild/images#1978
so lets update the unit test to match the new and more exact
error.

Author: mvo5

pkg/progress/command_test.go

@@ -64,7 +64,7 @@ done
 	pbar, err := progress.New("debug")
 	assert.NoError(t, err)
 	err = progress.RunOSBuild(pbar, []byte(`{"fake":"manifest"}`), nil, nil)
-	assert.EqualError(t, err, `error parsing osbuild status, please report a bug and try with "--progress=verbose": cannot scan line "invalid-json": invalid character 'i' looking for beginning of value`)
+	assert.EqualError(t, err, `error parsing osbuild status, please report a bug and try with "--progress=verbose": cannot scan line "invalid-json\n": invalid character 'i' looking for beginning of value`)
 
 	// ensure the SIGINT got delivered
 	var pathExists = func(p string) bool {