dont override global warning (apache#1350)

* dont override global

* add back warning filter

Author: kevinjqliu

pyiceberg/utils/deprecated.py

@@ -55,11 +55,10 @@ def deprecation_message(deprecated_in: str, removed_in: str, help_message: Optio
 
 
 def _deprecation_warning(message: str) -> None:
-    warnings.simplefilter("always", DeprecationWarning)  # turn off filter
-
-    warnings.warn(
-        message,
-        category=DeprecationWarning,
-        stacklevel=2,
-    )
-    warnings.simplefilter("default", DeprecationWarning)  # reset filter
+    with warnings.catch_warnings():  # temporarily override warning handling
+        warnings.simplefilter("always", DeprecationWarning)  # turn off filter
+        warnings.warn(
+            message,
+            category=DeprecationWarning,
+            stacklevel=2,
+        )

pyproject.toml

@@ -909,6 +909,8 @@ filterwarnings = [
   "ignore:unclosed <socket.socket",
   # Remove this in a future release of PySpark.
   "ignore:distutils Version classes are deprecated. Use packaging.version instead.",
+  # Remove this in a future release of PySpark. https://github.com/apache/iceberg-python/issues/1349
+  "ignore:datetime.datetime.utcfromtimestamp\\(\\) is deprecated and scheduled for removal in a future version.",
   # Remove this once https://github.com/boto/boto3/issues/3889 is fixed.
   "ignore:datetime.datetime.utcnow\\(\\) is deprecated and scheduled for removal in a future version.",
 ]