Use RELEASE_CANDIDATE_TAG_NAME variable

Author: sgilmore10

.github/workflows/release.yml

@@ -58,9 +58,8 @@ jobs:
           echo "RC_NUM=${rc_num}" >> ${GITHUB_ENV}
       - name: Download Release Candidate Artifacts 
         run: |
-          rc_tag=apache-arrow-${VERSION}-rc${RC_NUM}
           mkdir release_candidate_artifacts
-          gh release download ${rc_tag} --dir release_candidate_artifacts
+          gh release download ${RELEASE_CANDIDATE_TAG_NAME} --dir release_candidate_artifacts
       - name: Create Release Title
         run: |
           title="Apache Arrow ${VERSION}"