Remove hard-coded muon location for serialisation configuration

As discussed in !685 (merged), when running the real-time reconstruction there is a single muon-related TES location which is unreachable in the configuration. This causes an error during serialisation because the ANN service does not have an entry for this location.

With !684 (closed) (which is superseded by !1141 (merged)), the muon ID algorithm should no longer have this problem, and so the hard-coded location can be removed.