metrics auth responders keep the last good bearer while the store doesn't answer

swarm-metrics-auth/Cargo.toml

@@ -10,6 +10,8 @@ path = "src/main.rs"
 [dependencies]
 anyhow.workspace = true
 axum.workspace = true
+# The read time in the fallback log line.
+chrono.workspace = true
 clap.workspace = true
 serde.workspace = true
 # Comparing the presented bearer with the stored one.
@@ -25,4 +27,5 @@ workspace = true
 # `test-util` for `#[tokio::test(start_paused = true)]`: the lookup-timeout
 # test waits out `LOOKUP_TIMEOUT` on paused time.
 [dev-dependencies]
+mockall.workspace = true
 tokio = { workspace = true, features = ["test-util"] }