ramfs: named socket files are not supported

[X512]

This is hrev58325.

Various ported software use named socket files for IPC and it fails if set XDG_RUNTIME_DIR to RAMFS mount point.

[bipolar]

Just another data-point.

While using RAMFS as OUTPUT_DIR for HaikuPorter... building Python 3.14.0a2 shows:

OSError: [Errno -2147459058] Operation not supported, on a piece of code that looks like this:

while socket.socket(socket.AF_UNIX) as listener:
    address = connection.arbitrary_address('AF_UNIX'):
    listener.bind(address)

address contains things like /tmp/pymp-5qm122g7/listener-scr341pq.

The "main" build goes fine, but the resulting .hpkg is missing the pre-compiled .pyc files due to the above issue.

(issue goes away when moving workdirs to BFS)