Restrict ceph mon hook execution

This commit adds a condition to run the ceph mon removal hook
only when rolling back to stx-8, which is the only scenario
where it is needed, and it causes issues if ran in other upgrade
paths. This commit also adds a TODO reminder to remove this hook
in the future when it is not needed anymore.

Test Plan (only affects AIO-DX)
PASS: AIO-DX - stx-10 -> stx-8 rollback successful
PASS: AIO-DX - stx-11 -> stx-10 rollback successful

Story: 2010676
Task: 51307

Change-Id: I5447deaa202fd78e983be26a9a230848bc2bc04e
Signed-off-by: Heitor Matsui <heitorvieira.matsui@windriver.com>

software/software/agent_hooks.py

@@ -304,13 +304,23 @@ class RemoveKubernetesConfigSymlinkHook(BaseHook):
                 raise
 
 
+# TODO(heitormatsui): delete in the future, not needed for stx-10 -> <future-releases>
 class RemoveCephMonHook(BaseHook):
     """
     Remove additional ceph-mon added for each controller
     """
     PMON_FILE = "/etc/pmon.d/ceph-fixed-mon.conf"
 
+    def __init__(self, attrs):
+        super().__init__(attrs)
+        self._major_release = None
+        if "major_release" in attrs:
+            self._major_release = attrs.get("major_release")
+
     def run(self):
+        # (DX only) on 22.12 there is 1 mon, on 24.09 there are 3
+        # so only in 24.09 -> 22.12 rollback this hook is needed
+        if self._major_release == "22.12":
             system_type = utils.get_platform_conf("system_type")
             system_mode = utils.get_platform_conf("system_mode")
             nodetype = utils.get_platform_conf("nodetype")