`performance_bin` fails if `--states` path doesn't end with trailing slash `/`

[tangruize]

When running performance_bin commands in tutorial, if the path of --states argument doesn't end with /, the command fails:

# This fails
bazel-bin/performance/performance_bin \
  --states samples/simple-coin/out/run_2024-05-07_23-46-17  \
  --source samples/simple-coin/CoinToss.json

# This works
bazel-bin/performance/performance_bin \
  --states samples/simple-coin/out/run_2024-05-07_23-46-17/  \
  --source samples/simple-coin/CoinToss.json

The root cause is:

fizzbee/performance/files.py

Lines 40 to 46 in 7004a5e

	pattern = os.path.join(f"{path_prefix}*adjacency_lists_*.pb")
	links = graph.Links()
	return load_proto_files(pattern, links)
	def load_nodes_from_proto_files(path_prefix):
	pattern = os.path.join(f"{path_prefix}*nodes_*.pb")

A potential fix:

def load_adj_lists_from_proto_files(path_prefix):
    pattern = os.path.join(path_prefix, "adjacency_lists_*.pb")
    links = graph.Links()
    return load_proto_files(pattern, links)


def load_nodes_from_proto_files(path_prefix):
    pattern = os.path.join(path_prefix, "nodes_*.pb")
    pb = graph.Nodes()
    return load_proto_files(pattern, pb)