DOCSP-45604 -- fix typo (#2001)

Author: jvincent-mongodb

.backportrc.json

@@ -2,7 +2,7 @@
     "repoOwner": "10gen",
     "repoName": "docs-k8s-operator",
 
-    "targetBranchChoices": ["1.29", "v1.28", "v1.27", "v1.26", "v1.25", "v1.24"],
+    "targetBranchChoices": ["v1.29", "v1.28", "v1.27", "v1.26", "v1.25", "v1.24"],
 
     "editor": "code",