Remove pointless map_err calls.

src/error/error.rs

@@ -35,3 +35,9 @@ impl From<&'static str> for CustomError {
         CustomError::Static(value)
     }
 }
+
+impl From<String> for CustomError {
+    fn from(value: String) -> Self {
+        CustomError::Text(value)
+    }
+}