chore: remove code nothing uses

Each was checked with git grep across every tracked file (templates, JS,
shell, unit files and the extensionless console daemons) and for
dynamic use (URL names, template names, registries):

- vrtManager: host_is_up, is_kvm_supported, get_emulators,
  get_file_extensions, both get_network_forward, get_snapshots,
  get_storages_images, get_os_type, get_host_arch, the get_pretty_* trio
  and, in util, is_kvm_available, randomMAC, get_max_vcpus, compareMAC,
  pretty_mem, pretty_bytes and validate_uuid; with them the port
  constants only host_is_up read. Some were reached only by their tests,
  which go too.
- The flavor edit page: nothing linked to it; flavors are created and
  deleted on the Flavors page and edited through the API.
- computes.validate_name, UserForm.identity_has_errors, the has_perm
  template tag, the ALLOW_EMPTY_PASSWORD setting nothing reads,
  hidePleaseWaitDialog, default_app_config (ignored since Django 4.1)
  and the Python < 3.6 lines of secret_generator.py.

vrtManager/connection.py

@@ -3,8 +3,6 @@ import contextlib
 import io
 import logging
 import os
-import re
-import socket
 import threading
 import time
 import uuid
@@ -23,9 +21,6 @@ CONN_SOCKET = 4
 CONN_TLS = 3
 CONN_SSH = 2
 CONN_TCP = 1
-TLS_PORT = 16514
-SSH_PORT = 22
-TCP_PORT = 16509
 
 # libvirt has no timeout for opening a connection: an unreachable host
 # blocks for the kernel's TCP connect timeout (about 2 minutes), a daemon
@@ -457,34 +452,6 @@ class wvmConnectionManager(object):
             raise util.ConnectionFailed(error["text"], **error["values"])
         return live
 
-    def host_is_up(self, conn_type, hostname, timeout=1):
-        """True if the libvirt endpoint of hostname accepts a TCP (or Unix
-        socket) connection. This is a reachability probe only: it does not
-        check credentials or libvirt itself. hostname may carry a port
-        ("host:port", "[v6]:port")."""
-        if conn_type == CONN_SOCKET:
-            sock = socket.socket(socket.AF_UNIX, socket.SOCK_STREAM)
-            try:
-                sock.settimeout(timeout)
-                sock.connect("/var/run/libvirt/libvirt-sock")
-                return True
-            except OSError:
-                return False
-            finally:
-                sock.close()
-        default_port = {CONN_SSH: SSH_PORT, CONN_TCP: TCP_PORT, CONN_TLS: TLS_PORT}.get(conn_type)
-        if default_port is None:
-            return False
-        host, port = str(hostname), default_port
-        match = re.fullmatch(r"\[?([^\[\]]+?)\]?:(\d+)", host)
-        if match and (host.startswith("[") or host.count(":") == 1):
-            host, port = match.group(1), int(match.group(2))
-        try:
-            with socket.create_connection((host.strip("[]"), port), timeout=timeout):
-                return True
-        except OSError:
-            return False
-
 connection_manager = wvmConnectionManager(
     settings.LIBVIRT_KEEPALIVE_INTERVAL if hasattr(settings, "LIBVIRT_KEEPALIVE_INTERVAL") else 5,
     settings.LIBVIRT_KEEPALIVE_COUNT if hasattr(settings, "LIBVIRT_KEEPALIVE_COUNT") else 5,
@@ -633,12 +600,6 @@ class wvmConnect(object):
         release = ver
         return f"{major}.{minor}.{release}"
 
-    def is_kvm_supported(self):
-        """
-        :return: kvm support or not
-        """
-        return util.is_kvm_available(self.get_cap_xml())
-
     def get_storages(self, only_actives=False):
         """
         :return: list of active or all storages
@@ -776,21 +737,6 @@ class wvmConnect(object):
 
         return util.get_xml_path(self.get_cap_xml(), func=machines)
 
-    def get_emulators(self):
-        """
-        :return: host emulators list
-        """
-
-        def emulators(ctx):
-            result = {}
-            for arch in ctx.xpath("/capabilities/guest/arch"):
-                emulator = arch.xpath("emulator")
-                arch_name = arch.xpath("@name")[0]
-                result[arch_name] = emulator
-            return result
-
-        return util.get_xml_path(self.get_cap_xml(), func=emulators)
-
     def get_os_loaders(self, arch="x86_64", machine="pc"):
         """
         :param arch: architecture
@@ -922,12 +868,6 @@ class wvmConnect(object):
         """
         return ["raw", "qcow", "qcow2"]
 
-    def get_file_extensions(self):
-        """
-        :return: available image filename extensions
-        """
-        return ["img", "qcow", "qcow2"]
-
     def get_video_models(self, arch, machine):
         """
         :param arch: architecture
@@ -1105,15 +1045,6 @@ class wvmConnect(object):
     def get_network(self, net):
         return self.wvm.networkLookupByName(net)
 
-    def get_network_forward(self, net_name):
-        def get_forward(doc):
-            forward_mode = util.get_xpath(doc, "/network/forward/@mode")
-            return forward_mode or "isolated"
-
-        net = self.get_network(net_name)
-        xml = net.XMLDesc(0)
-        return util.get_xml_path(xml, func=get_forward)
-
     def get_nwfilter(self, name):
         return self.wvm.nwfilterLookupByName(name)
 
@@ -1229,18 +1160,6 @@ class wvmConnect(object):
                 paths += [v for v in (source.get("file"), source.get("dev"), source.get("name")) if v]
         return paths
 
-    def get_snapshots(self):
-        instance = []
-        for snap_id in self.wvm.listDomainsID():
-            dom = self.wvm.lookupByID(int(snap_id))
-            if dom.snapshotNum(0) != 0:
-                instance.append(dom.name())
-        for name in self.wvm.listDefinedDomains():
-            dom = self.wvm.lookupByName(name)
-            if dom.snapshotNum(0) != 0:
-                instance.append(dom.name())
-        return instance
-
     def can_change_interfaces(self):
         """Whether the host's libvirt can define interfaces: the udev backend
         only reads them. The definition sent is invalid, so nothing is