CodeQL's `rust/cleartext-logging` rule (alert #7) taints any value
returned by a function whose name contains "secret" — it can't tell
configuration metadata (the binding identifier from edgezero.toml)
from secret material. The previous rename
`secret_store_name → secret_store_binding` did NOT defeat the
heuristic because "secret" is still in the function name.

Real fix: stop logging the binding name. Operators can read their
own `edgezero.toml` to verify which store binding was configured.
The presence message ("secrets enabled for axum") is still emitted,
which is the only thing the log line was actually load-bearing for.

Updated the affected unit test assertion to match the new wording.