Nit: Make DataScan::_check_sequence_number static (#2196)

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# Rationale for this change

Silence PyCharm warning that `DataScan::_check_sequence_number` can be
static.

# Are these changes tested?

N/A

# Are there any user-facing changes?

No

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Co-authored-by: Sreesh Maheshwar <smaheshwar@palantir.com>

Author: smaheshwar-pltr

pyiceberg/table/__init__.py

@@ -1857,7 +1857,8 @@ def _build_residual_evaluator(self, spec_id: int) -> Callable[[DataFile], Residu
             )
         )
 
-    def _check_sequence_number(self, min_sequence_number: int, manifest: ManifestFile) -> bool:
+    @staticmethod
+    def _check_sequence_number(min_sequence_number: int, manifest: ManifestFile) -> bool:
         """Ensure that no manifests are loaded that contain deletes that are older than the data.
 
         Args: