Merge pull request kubernetes#57376 from juju-solutions/bug/more-lint

Automatic merge from submit-queue. If you want to cherry-pick this change to another branch, please follow the instructions <a href="https://github.com/kubernetes/community/blob/master/contributors/devel/cherry-picks.md">here</a>.

Minor lint fix on Juju master

**What this PR does / why we need it**: Fix lint error in master

**Which issue(s) this PR fixes** *(optional, in `fixes #<issue number>(, fixes #<issue_number>, ...)` format, will close the issue(s) when PR gets merged)*:
Fixes #

**Special notes for your reviewer**:

**Release note**:

```NONE

```

cluster/juju/layers/kubernetes-master/reactive/kubernetes_master.py

@@ -39,7 +39,7 @@
 from charms.reactive import remove_state
 from charms.reactive import set_state
 from charms.reactive import is_state
-from charms.reactive import when, when_any, when_not, when_all
+from charms.reactive import when, when_any, when_not
 from charms.reactive.helpers import data_changed, any_file_changed
 from charms.kubernetes.common import get_version
 from charms.kubernetes.common import retry