Update test-nvim.yml

.github/workflows/test-nvim.yml

@@ -31,6 +31,7 @@ jobs:
           echo "Finished git checkout in $GITHUB_WORKSPACE"
           # not using apt as repos may lag behind
           curl -LO https://github.com/neovim/neovim/releases/latest/download/nvim.appimage
+          chmod +x nvim.appimage
           ./nvim.appimage --appimage-extract
           sudo mv squashfs-root /
           sudo ln -s /squashfs-root/AppRun /usr/bin/nvim