Fix SSL deactivation using catalog properties (#3012)

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Closes #2985 

# Rationale for this change

## Are these changes tested?
Yes

## Are there any user-facing changes?

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Author: MenelikV

pyiceberg/catalog/rest/__init__.py

@@ -363,7 +363,7 @@ def _create_session(self) -> Session:
 
         # Sets the client side and server side SSL cert verification, if provided as properties.
         if ssl_config := self.properties.get(SSL):
-            if ssl_ca_bundle := ssl_config.get(CA_BUNDLE):
+            if (ssl_ca_bundle := ssl_config.get(CA_BUNDLE)) is not None:
                 session.verify = ssl_ca_bundle
             if ssl_client := ssl_config.get(CLIENT):
                 if all(k in ssl_client for k in (CERT, KEY)):

tests/catalog/test_rest.py

@@ -1643,6 +1643,19 @@ def test_update_namespace_properties_invalid_namespace(rest_mock: Mocker) -> Non
     assert "Empty namespace identifier" in str(e.value)
 
 
+def test_with_disabled_ssl_ca_bundle(rest_mock: Mocker) -> None:
+    # Given
+    catalog_properties = {
+        "uri": TEST_URI,
+        "token": TEST_TOKEN,
+        "ssl": {
+            "cabundle": False,
+        },
+    }
+    catalog = RestCatalog("rest", **catalog_properties)  # type: ignore
+    assert catalog._session.verify is False
+
+
 def test_request_session_with_ssl_ca_bundle(monkeypatch: pytest.MonkeyPatch) -> None:
     # Given
     catalog_properties = {