Revert multipath.conf from machine.files

Removes /etc/multipath.conf from machine.files section which causes
jungle-cruise boot failure. This reverts the problematic change from
commit adc415e.

Root cause: Writing /etc/multipath.conf during early boot via machine.files
causes writeUserFiles to fail on read-only filesystem.

Solution: Use DaemonSet (iscsi-multipath-init.yaml) to write multipath.conf
after boot when filesystem is fully writable.

Fixes: jungle-cruise NotReady status (kubelet stopped posting)

talos/talhelper/talconfig.yaml

@@ -155,36 +155,6 @@ worker:
           net.ipv4.conf.all.arp_announce: "2"
           net.ipv4.conf.all.arp_ignore: "1"
 
-        # Write multipath.conf for PX-CSI
-        # PX-CSI node driver requires this file to exist
-        files:
-          - content: |
-              defaults {
-                polling_interval 10
-              }
-              devices {
-                device {
-                  vendor "PURE"
-                  product "*"
-                  path_selector "round-robin 0"
-                  path_grouping_policy group_by_prio
-                  prio alua
-                  failback immediate
-                  path_checker tur
-                  fast_io_fail_tmo 10
-                  user_friendly_names no
-                  no_path_retry 0
-                  features "0"
-                  dev_loss_tmo 60
-                }
-              }
-              blacklist {
-                devnode "^(ram|raw|loop|fd|md|dm-|sr|scd|st)[0-9]*"
-                devnode "^hd[a-z]"
-              }
-            path: /etc/multipath.conf
-            permissions: 0644
-
 # ─── Nodes ───────────────────────────────────────────────────────────────────
 nodes:
   # ── Control plane ──────────────────────────────────────────────────────────