autopilot: update AttachmentHeuristics with context

Continue threading context through the autopilot system and remove the
remaining context.TODOs.

autopilot/top_centrality_test.go

@@ -1,6 +1,7 @@
 package autopilot
 
 import (
+	"context"
 	"testing"
 
 	"github.com/btcsuite/btcd/btcec/v2"
@@ -58,7 +59,7 @@ func testTopCentrality(t *testing.T, graph testGraph,
 		// Attempt to get centrality scores and expect
 		// that the result equals with the expected set.
 		scores, err := topCentrality.NodeScores(
-			graph, channels, chanSize, nodes,
+			context.Background(), graph, channels, chanSize, nodes,
 		)
 
 		require.NoError(t, err)