docs: add additional breaking changes to the 1.7 upgrade guide (#8492)

Author: jmdeal

website/content/en/preview/upgrading/upgrade-guide.md

@@ -97,9 +97,11 @@ Karpenter `1.1.0` drops the support for `v1beta1` APIs.
   - Karpenter now creates instance profiles with a specific path structure `/karpenter/{region}/{cluster-name}/{nodeclass-uid}/` instead of the generic root path `/`
   - This change helps with better organization and management of instance profiles
   - No action is required for existing instance profiles, but new ones will use this path structure
-* Additional IAM permissions required:
-  - The following new IAM permissions are required for the Karpenter controller role:
-    - `iam:ListInstanceProfiles`: Required for managing instance profiles
+  - Additional IAM permissions required:
+    - The following new IAM permissions are required for the Karpenter controller role:
+      - `iam:ListInstanceProfiles`: Required for managing instance profiles
+* The `karpenter_pods_pods_drained_total` metric has been renamed to `karpenter_pods_drained_total`
+* The `karpenter_nodeclaims_disrupted_total` metric reason `liveness` has been renamed to `registration_timeout`
 
 ### Upgrading to `1.6.0`+