Production error logging to System.out in IpcServer

[elharo]

Affected version: HEAD

File: maven-resolver-named-locks-ipc/src/main/java/org/eclipse/aether/named/ipc/IpcServer.java:196

private static void error(String msg, Throwable t) {
    System.out.println("[ipc] [error] " + msg);
    t.printStackTrace(System.out);
}

All errors in the IPC server go to stdout instead of a proper logging framework (SLF4J). In a production Maven build, these messages are invisible or interleaved with build output. Same issue for debug() (line 184) and info() (line 190) in the same file.

Originally reported in #1944.