Use exact ref to get branch SHA1

[ErikJiang]

See the CI error log for：ensure valid branch and commit

Run INPUTS_SPRAY_REF=c13134b88117bc35d05b77c26e1cc5f80aea5624 2d0cc2b4ea1a5f578300536d711d10c626c390bb
  INPUTS_SPRAY_REF=c13134b88117bc35d05b77c[2](https://github.com/kubean-io/kubean/actions/runs/16213707874/job/45778451024#step:2:2)6e1cc5f80aea5624 2d0cc2b4ea1a5f578300536d711d10c626c390bb
  SPRAY_SHA=`git ls-remote https://github.com/kubernetes-sigs/kubespray.git ${INPUTS_SPRAY_REF} | awk '{ print $1}'`
  if [[ -z "${SPRAY_SHA}" ]];then
    if (( ${#INPUTS_SPRAY_REF} != 40 ));then
      echo "The sha length of the commit must be 40"
      exit 1
    fi
    SPRAY_SHA=${INPUTS_SPRAY_REF}
  fi
  echo image_tag_short_sha=$(echo ${SPRAY_SHA} | cut -c 1-7) >> $GITHUB_OUTPUT
  
  echo dockerfile_commit=$(curl -L \
    -H "Accept: application/vnd.github+json" \
    -H "Authorization: ***" \
    -H "X-GitHub-Api-Version: 2022-11-28" \
    https://api.github.com/repos/${GITHUB_REPOSITORY}/commits?path=build/images/kubespray/Dockerfile \
    |jq '.[0].sha' | tr -d '"') >> $GITHUB_OUTPUT
  shell: /usr/bin/bash -e {0}
/home/runner/work/_temp/fbb[3](https://github.com/kubean-io/kubean/actions/runs/16213707874/job/45778451024#step:2:3)e190-28f3-4286-ac81-ec6014391f78.sh: line 1: 2d0cc2b4ea1a5f578300536d711d10c626c390bb: command not found
Error: Process completed with exit code 127.

There are two sha1 values ​​obtained by INPUTS_SPRAY_REF, which is obviously abnormal. It should be caused by the lack of precise filtering when git gets branch sha1.