docs: fix ci gather branches and tags

Author: liukj

.github/workflows/build-docs.yml

@@ -52,7 +52,7 @@ jobs:
 
           # Gather branches and tags, filter for semantic versions, sort, remove duplicates
           VERSIONS=$(git for-each-ref refs/remotes/origin refs/tags --format="%(refname:short)" | \
-            grep -E "^v[0-9]+\.[0-9]+\.[0-9]+$" | sort -Vr | uniq | tr '\n' ',' | sed 's/,$//')
+            grep -E "^[0-9]+\.[0-9]+\.[0-9]+$" | awk -F'[v]' '{print "v"$2}' | sort -Vr | uniq | tr '\n' ',' | sed 's/,$//')
           echo "VERSIONS=main,$VERSIONS" >> $GITHUB_ENV
 
       - name: Install Hugo