chore: semantic release breaking changes

semantic release 16.0.0 introduced these breaking changes:

> The branch option has been removed in favor of branches

> The new branches option expect either an Array or a single branch definition. To migrate your configuration:

> If you want to publish package from multiple branches, please see the configuration documentation
> If you use the default configuration and want to publish only from master: nothing to change
> If you use the branch configuration and want to publish only from one branch: replace branch with branches ("branch": "my-release-branch" => "branches": "my-release-branch")

this commit aligns our semantic release config to the new format

Author: Shesekino

package.json

@@ -63,7 +63,7 @@
     "url": "https://github.com/snyk/kubernetes-monitor.git"
   },
   "release": {
-    "branch": "staging",
+    "branches": "staging",
     "verifyConditions": [
       "@semantic-release/github"
     ],