chore: revert to old setup structure for ferc1 output test

The main improvement I see to the test setup is to make the graph definitions more atomic.
Currently we have the graph definitions split between node creation in setup and edge definition in the tests themselves.

test/unit/output/ferc1_test.py

@@ -37,8 +37,6 @@
 
 
 class TestForestSetup:
-    """Base class for forest testing."""
-
     def _exploded_calcs_from_edges(self, edges: list[tuple[NodeId, NodeId]]):
         records = []
         for parent, child in edges:
@@ -86,10 +84,8 @@ def build_forest_and_annotated_tags(
         return annotated_tags
 
 
-class TestPrunnedNode(TestForestSetup):
-    @pytest.fixture(autouse=True)
-    def setup_nodes(self):
-        """Setup nodes for testing."""
+class TestPrunedNode(TestForestSetup):
+    def setup_method(self):
         self.root = NodeId(
             table_name="table_1",
             xbrl_factoid="reported_1",
@@ -120,7 +116,6 @@ def setup_nodes(self):
         )
 
     def test_pruned_nodes(self):
-        """Test pruned nodes."""
         edges = [(self.root, self.root_child), (self.root_other, self.root_other_child)]
         tags = pd.DataFrame(columns=list(NodeId._fields)).convert_dtypes()
         forest = XbrlCalculationForestFerc1(
@@ -133,11 +128,7 @@ def test_pruned_nodes(self):
 
 
 class TestTagPropagation(TestForestSetup):
-    """Test tag propagation functionality."""
-
-    @pytest.fixture(autouse=True)
-    def setup_nodes(self):
-        """Setup nodes for testing."""
+    def setup_method(self):
         self.parent = NodeId(
             table_name="table_1",
             xbrl_factoid="reported_1",
@@ -189,7 +180,6 @@ def setup_nodes(self):
         )
 
     def test_leafward_prop_undecided_children(self):
-        """Test leadward propagation with undecided children."""
         edges = [(self.parent, self.child1), (self.parent, self.child2)]
         tags = pd.DataFrame([self.parent, self.child1, self.child2]).assign(
             in_rate_base=["yes", pd.NA, pd.NA]
@@ -374,7 +364,6 @@ def test_annotated_forest_propagates_rootward_two_layers_plus_corrections(self):
 
 
 def test_get_core_ferc1_asset_description():
-    """Test core FERC1 asset description extraction."""
     valid_core_ferc1_asset_name = "core_ferc1__yearly_income_statements_sched114"
     valid_core_ferc1_asset_name_result = get_core_ferc1_asset_description(
         valid_core_ferc1_asset_name