Update weight formatting in composed.go

Changed weight string format from three to eighteen decimal places for consistency with expected precision. This ensures compliance with the required 18 decimal places format for weights in the composed stream setup.

internal/contracts/tests/utils/setup/composed.go

@@ -188,7 +188,7 @@ func setTaxonomy(ctx context.Context, input SetTaxonomyInput) error {
 		primitiveStreamStrings = append(primitiveStreamStrings, item.ChildStream.StreamId.String())
 		dataProviderStrings = append(dataProviderStrings, item.ChildStream.DataProvider.Address())
 		// should be formatted as 0.000000000000000000 (18 decimal places)
-		weightStrings = append(weightStrings, fmt.Sprintf("%.3f", item.Weight))
+		weightStrings = append(weightStrings, fmt.Sprintf("%.18f", item.Weight))
 	}
 
 	dbid := utils.GenerateDBID(input.composedStream.StreamId.String(), input.Platform.Deployer)