use cache/save to avoid restore

Author: mitchcapper

.github/workflows/gnulib_tests.yml

@@ -32,7 +32,7 @@ jobs:
       - name: clone srcs
         run: git clone --bare git://git.sv.gnu.org/gnulib.git d:/WLB/gnulib.git
       - name: Cache gnulib bare repo
-        uses: actions/cache@v4
+        uses: actions/cache/save@v4
         with:
           path: d:/WLB/gnulib.git
           key: gnulib-bare