Try fixing tag.

Author: Alexhuszagh

.github/workflows/ci.yml

@@ -165,12 +165,12 @@ jobs:
         run: docker save "${IMAGE}:${TAG}" -o "${IMAGE}-${TAG}.tar"
         env:
             IMAGE: ${{ matrix.image }}
-            TAG: ${{ github.ref.name }}
+            TAG: ${{ env.GITHUB_REF_NAME }}
 
       - uses: actions/upload-artifact@v2
         with:
           name: ${{ matrix.image }}-image-tarball
-          path: ${{ matrix.image }}-${{ github.ref.name }}.tar
+          path: ${{ matrix.image }}-${{ env.GITHUB_REF_NAME }}.tar
 
       - uses: ./.github/actions/cargo-install-upload-artifacts
         if: matrix.deploy