Add changelog entry for PR#3892

Author: solrbot

changelog/unreleased/PR#3892-update-actions-checkout-action.yml

@@ -0,0 +1,7 @@
+title: Update actions/checkout action to v6
+type: dependency_update
+authors:
+- name: solrbot
+links:
+- name: PR#3892
+  url: https://github.com/apache/solr/pull/3892