fix: Add Python-v1 to allowed-labels for label creation

The Python-v1 label was added to label-ruleset.yml in #8074 but not to
allowed-labels.yml, so the label was never created in the repo and could
not be selected or auto-applied. Add the matching label definition so the
label-auditor workflow creates it.

Author: brmur

.github/allowed-labels.yml

@@ -75,6 +75,9 @@
 - name: Python
   color: "f5f7f9"
   description: "This issue relates to the AWS SDK for Python (boto3)"
+- name: Python-v1
+  color: "f5f7f9"
+  description: "This issue relates to the AWS SDK for Python"
 - name: Ruby
   color: "f5f7f9"
   description: "This issue relates to the AWS SDK for Ruby"