Tag release after updating gradle.properties

Closes gh-11023

Author: eleftherias

.github/workflows/release-next-version.yml

@@ -97,6 +97,7 @@ jobs:
           ./gradlew :spring-security-docs:antoraUpdateVersion
           updatedVersion=$(cat gradle.properties | grep "version=" | awk -F'=' '{print $2}')
           git commit -am "Release $updatedVersion"
+          git tag $updatedVersion
           git push
   notify_result:
     name: Check for failures