- api_client: unused CLI command that just queried a server and printed
its statistics
- maps / swhid.py: was used to translate the mappings of the SWHIDs to
node IDs. Now one of the mappings has disappeared (MPH is used
instead) and this translation entirely happens in the Java side. This
entire code is no longer needed.
- cachemount: can be trivially replaced by a simple systemd service,
already how it currently is set up in production:
```
[Service]
Type=oneshot
RemainAfterExit=yes
ExecStart=mkdir -p /dev/shm/swh-graph/default
ExecStart=sh -c "ln -s /.../compressed/* /dev/shm/swh-graph/default"
ExecStart=sh -c "cp --remove-destination /.../compressed/graph.graph /dev/shm/swh-graph/default"
ExecStart=sh -c "cp --remove-destination /.../compressed/graph-transposed.graph /dev/shm/swh-graph/default"
ExecStop=rm -rf /dev/shm/swh-graph/default
```
Prod should decide what are the correct tradeoffs as to what should be
put in ram and what should be symlinked, instead of leaving that
responsibility to the cachemount command.