doc(upgrade): auto image cleanup not working in some upgrade paths

Adding notes about the automatic image cleanup issue for the following upgrade paths:
- Upgrading from v1.3.1 to v1.3.2
- Upgrading from v1.2.2 to v1.3.1

Signed-off-by: Zespre Chang <zespre.chang@suse.com>

docs/upgrade/v1-2-2-to-v1-3-1.md

@@ -87,3 +87,9 @@ To resolve this issue, perform the following steps:
   - [[BUG] Upgrade v1.2.2->v1.3.1 stuck at Waiting for kubelet to update, even the node has been updated](https://github.com/harvester/harvester/issues/6041)
 
 ---
+
+### 2. Automatic image cleanup is not functioning
+
+Due to an incomplete image list packaged in the published ISO image, the automatic image cleanup procedure will not work when users upgrade Harvester from v1.2.2 to v1.3.1. This does not impact the Harvester upgrade as a whole. To clean up container images manually after the upgrade ends, please refer to the [script](https://github.com/harvester/upgrade-helpers/blob/main/bin/harv-purge-images.sh). For more information, see [issue #6620](https://github.com/harvester/harvester/issues/6620).
+
+---

docs/upgrade/v1-3-1-to-v1-3-2.md

@@ -220,3 +220,9 @@ If the kubectl command does not return a response, the kubelet is unable to acce
 For more information, see [Issue #6432](https://github.com/harvester/harvester/issues/6432#issuecomment-2325488465).
 
 ---
+
+### 2. Automatic image cleanup is not functioning
+
+Due to an incomplete image list packaged in the published ISO image, the automatic image cleanup procedure will not work when users upgrade Harvester from v1.3.1 to v1.3.2. This does not impact the Harvester upgrade as a whole. To clean up container images manually after the upgrade ends, please refer to the [script](https://github.com/harvester/upgrade-helpers/blob/main/bin/harv-purge-images.sh). For more information, see [issue #6620](https://github.com/harvester/harvester/issues/6620).
+
+---

versioned_docs/version-v1.3/upgrade/v1-2-2-to-v1-3-1.md

@@ -87,3 +87,9 @@ To resolve this issue, perform the following steps:
   - [[BUG] Upgrade v1.2.2->v1.3.1 stuck at Waiting for kubelet to update, even the node has been updated](https://github.com/harvester/harvester/issues/6041)
 
 ---
+
+### 2. Automatic image cleanup is not functioning
+
+Due to an incomplete image list packaged in the published ISO image, the automatic image cleanup procedure will not work when users upgrade Harvester from v1.2.2 to v1.3.1. This does not impact the Harvester upgrade as a whole. To clean up container images manually after the upgrade ends, please refer to the [script](https://github.com/harvester/upgrade-helpers/blob/main/bin/harv-purge-images.sh). For more information, see [issue #6620](https://github.com/harvester/harvester/issues/6620).
+
+---

versioned_docs/version-v1.3/upgrade/v1-3-1-to-v1-3-2.md

@@ -220,3 +220,9 @@ If the kubectl command does not return a response, the kubelet is unable to acce
 For more information, see [Issue #6432](https://github.com/harvester/harvester/issues/6432#issuecomment-2325488465).
 
 ---
+
+### 2. Automatic image cleanup is not functioning
+
+Due to an incomplete image list packaged in the published ISO image, the automatic image cleanup procedure will not work when users upgrade Harvester from v1.3.1 to v1.3.2. This does not impact the Harvester upgrade as a whole. To clean up container images manually after the upgrade ends, please refer to the [script](https://github.com/harvester/upgrade-helpers/blob/main/bin/harv-purge-images.sh). For more information, see [issue #6620](https://github.com/harvester/harvester/issues/6620).
+
+---