PERF: Reduce Python Row indexing overhead (#822)

### Work Item / Issue Reference

[AB#48366](https://sqlclientdrivers.visualstudio.com/c6d89619-62de-46a0-8b46-70b92a84d85e/_workitems/edit/48366)

### Summary
Add a two-line fast path in `Row.__getitem__` for indexes whose exact
type is `int`, returning the stored value directly. Keep the existing
fallback order unchanged for booleans, integer subclasses, slices and
column-name access.

Only `mssql_python/row.py` changes. No public API, native code, tests,
build configuration or CI changes are included.

Co-authored-by: Copilot App <223556219+Copilot@users.noreply.github.com>

Author: jahnvi480

mssql_python/row.py

@@ -222,6 +222,8 @@ def _apply_output_converters_optimized(self, values, converter_map):
 
     def __getitem__(self, index) -> Any:
         """Allow accessing by numeric index (row[0]) or column name (row["col"])."""
+        if type(index) is int:
+            return self._values[index]
         if isinstance(index, str):
             # A row built without a column map has no named columns, so any
             # string key is simply absent (KeyError), never a TypeError.