chore(deps): bump gremlinpython to 3.8 and adjust traversal source construction (#3370)

gremlinpython 3.8 removed both `Graph().traversal()` and the deprecated
`traversal().withGraph(Graph())` form. `Graph` is now an empty placeholder.

Add a `local_traversal_source()` helper in `_gremlin_init` that constructs
`GraphTraversalSource(Graph(), TraversalStrategies())` directly. This is
sufficient for the bytecode → Translator → query string path used by
`to_property_graph` (no remote connection needed).

Replace the two `Graph().traversal()` call sites in `to_property_graph`
with the new helper.

Side effect of the lock refresh: gremlinpython 3.8 added an `async-timeout`
dependency with a `<5` constraint, downgrading async-timeout from 5.0.1 to
4.0.3. `awswrangler` does not import async-timeout directly, so this is a
pure resolver consequence.

Author: kukushking

awswrangler/neptune/_gremlin_init.py

@@ -8,9 +8,15 @@
     from gremlin_python.process.anonymous_traversal import traversal
     from gremlin_python.process.graph_traversal import GraphTraversalSource, __
     from gremlin_python.process.translator import Translator
-    from gremlin_python.process.traversal import Cardinality, T
+    from gremlin_python.process.traversal import Cardinality, T, TraversalStrategies
     from gremlin_python.structure.graph import Edge, Graph, Path, Property, Vertex, VertexProperty
 
+    def local_traversal_source() -> "GraphTraversalSource":
+        # gremlinpython 3.8 removed Graph().traversal() and traversal().withGraph(Graph()).
+        # We only need a traversal source to build bytecode that the Translator turns into
+        # a query string — no remote connection or strategies are needed.
+        return GraphTraversalSource(Graph(), TraversalStrategies())
+
     __all__ = [
         "__",
         "Cardinality",
@@ -22,6 +28,8 @@
         "Property",
         "T",
         "Translator",
+        "TraversalStrategies",
+        "local_traversal_source",
         "traversal",
         "Vertex",
         "VertexProperty",

awswrangler/neptune/_neptune.py

@@ -170,7 +170,7 @@ def to_property_graph(
     ... )
     """
     # check if ~id and ~label column exist and if not throw error
-    g = gremlin.Graph().traversal()
+    g = gremlin.local_traversal_source()
     is_edge_df = False
     is_update_df = True
     if "~id" in df.columns:
@@ -198,7 +198,7 @@ def to_property_graph(
         if index > 0 and index + 1 % batch_size == 0:
             res = _run_gremlin_insert(client, g)
             if res:
-                g = gremlin.Graph().traversal()
+                g = gremlin.local_traversal_source()
 
     return _run_gremlin_insert(client, g)