ci: cache packages after install

Instead of at end of workflow

.github/actions/setup-arch/action.yml

@@ -9,8 +9,8 @@ runs:
       shell: bash
       run: echo "week=$(date +%Y-%U)" >> $GITHUB_OUTPUT
 
-    - name: Cache packages
-      uses: actions/cache@v4
+    - name: Restore package cache
+      uses: actions/cache/restore@v4
       with:
         path: /var/cache/pacman/pkg
         key: pacman-${{ steps.date.outputs.week }}-${{ hashFiles('.github/actions/setup-arch/action.yml') }}
@@ -37,3 +37,9 @@ runs:
 
         install_pkg cpptrace  # Dep for qs
         install_pkg quickshell-git
+
+    - name: Save packages to cache
+      uses: actions/cache/save@v4
+      with:
+        path: /var/cache/pacman/pkg
+        key: pacman-${{ steps.date.outputs.week }}-${{ hashFiles('.github/actions/setup-arch/action.yml') }}