github actions: detect pre-release with 'rc'

Signed-off-by: tsukinaha <sakuovds@gmail.com>

.github/workflows/build_release.yml

@@ -203,7 +203,7 @@ jobs:
         run: echo "TAG_NAME=$(git describe --tags --abbrev=0)" >> $GITHUB_OUTPUT
 
       - name: Set prerelease variable
-        if: startsWith(github.ref, 'refs/tags/v') && endsWith(github.ref, '-alpha')
+        if: startsWith(github.ref, 'refs/tags/v') && contains(github.ref, 'rc')
         run: echo "PRERELEASE=true" >> $GITHUB_ENV
 
       - name: Upload Github Assets