Investigate error log messages for `loopyWriter`

We have received multiple reports about error-level loopyWriter log messages that popped up recently:

2023-10-12T20:30:18.883066580Z {"component": "gitaly","subcomponent":"gitaly","level":"error","level":"info","msg":"[transport] [client-transport 0xc00abb86c0] Closing: connection error: desc = \"error reading from server:EOF\"","pid":1,"system":"system","time":"2023-10-12T20:30:18.882Z"}
2023-10-12T20:30:18.883113776Z {"component": "gitaly","subcomponent":"gitaly","level":"error","level":"info","msg":"[transport] [client-transport 0xc00abb86c0] loopyWriter exiting with error: transport closed by client","pid":1,"system":"system","time":"2023-10-12T20:30:18.883Z"}
2023-10-12T20:30:18.883133413Z {"component": "gitaly","subcomponent":"gitaly","level":"error","level":"info","msg":"[transport] [server-transport 0xc005cdf520] loopyWriter exiting with error: transport closed by client","pid":1,"system":"system","time":"2023-10-12T20:30:18.883Z"}

These log messages seem to be confused about the actual log level that should be used as they contain both log levels "error" and "info". These messages are likely benign, and an initial guess is that this log level confusion has been introduced with the recent logging refactorings.

We should investigate whether we can improve this and fix the log level so that the messages are reported at the correct log level.