Fix semver sorting

Author: piki

.buildkite/hooks/pre-command

@@ -2,7 +2,7 @@ set -eu
 
 git log -25000 --format='%H' | sort > tmp-log
 git show-ref | grep tags/mysql-8 | sort > tmp-tags
-export CONTAINER_SEMVER=$(join tmp-log tmp-tags | sort -k2 | tail -1 | cut -d- -f2)
+export CONTAINER_SEMVER=$(join tmp-log tmp-tags | sort -t. -n -k3 | tail -1 | cut -d- -f2)
 echo "Semantic version = \"${CONTAINER_SEMVER}\""
 
 export CONTAINER_SHORT_SHA=$(git log -1 --pretty='%h')