refactor(runtime): simplify AssetDir() (#2761)

* refactor(runtime): simplify AssetDir()

* test(runtime): remove cwd checks

runtime/runtime_test.go

@@ -0,0 +1,16 @@
+package config
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAssetDir(t *testing.T) {
+	t.Parallel()
+	// Test AssetDir
+	entries, err := AssetDir("syntax")
+	assert.NoError(t, err)
+	assert.Contains(t, entries, "go.yaml")
+	assert.True(t, len(entries) > 5)
+}