fix(db): add type ignore comments for MyPy compatibility

- Add type: ignore[no-any-return] for decorated method return
- Add type: ignore[misc] for untyped tenacity decorator

The tenacity library doesn't have type stubs, so we need to
suppress these MyPy warnings.

Author: Sakeeb91

db/executor.py

@@ -248,7 +248,7 @@ async def execute(
             )
 
             result.execution_time_ms = execution_time_ms
-            return result
+            return result  # type: ignore[no-any-return]
 
         except asyncio.TimeoutError as e:
             logger.error(
@@ -274,7 +274,7 @@ async def execute(
                 details={"error": str(e)},
             ) from e
 
-    @retry(
+    @retry(  # type: ignore[misc]
         retry=retry_if_exception_type((ConnectionError, OSError)),
         stop=stop_after_attempt(3),
         wait=wait_exponential(multiplier=1, min=2, max=10),