fix: Simplify DefaultValue handling

Author: jachym-tousek-keboola

internal/pkg/service/stream/mapping/table/column/renderer.go

@@ -148,15 +148,11 @@ func (r *Renderer) jsonPathCSVValue(c Path, ctx recordctx.Context) (string, erro
 		return value.String(), nil
 	} else if c.DefaultValue != nil {
 		// An error happened while processing the path, but we have a DefaultValue to use.
-		var result any = *c.DefaultValue
-
 		if c.RawString {
-			if stringValue, ok := result.(string); ok {
-				return stringValue, nil
-			}
+			return *c.DefaultValue, nil
 		}
 
-		return json.EncodeString(result, false)
+		return json.EncodeString(*c.DefaultValue, false)
 	}
 
 	return "", resultErr