ci: try to enable cache for nix store

using https://github.com/nix-community/cache-nix-action

.forgejo/workflows/check.yml

@@ -3,19 +3,30 @@ on: [pull_request]
 
 jobs:
   Check:
-    runs-on: nix-flakes
+    runs-on: ubuntu-latest
     steps:
+      - uses: https://github.com/nixbuild/nix-quick-install-action@v26
+        with:
+          nix_conf: |
+            substituters = https://cache.nixos.org/ https://nix-community.cachix.org
+            trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs=
+            keep-outputs = true
+      - name: Restore and cache Nix store
+        uses: https://github.com/nix-community/cache-nix-action@v4
+        with:
+          key: cache-x86_64-linux-${{ hashFiles('**/*.nix') }}
+          restore-keys: |
+            cache-x86_64-linux-
+      
+          gc-linux: true
+          gc-max-store-size-linux: 10000000000
+          
+          purge-caches: true
+          purge-key: cache-x86_64-linux-
+          purge-created: true
+          purge-created-max-age: 42
       - name: Check out repository code
         uses: https://code.forgejo.org/actions/checkout@v4
-      - name: "Cache Nix store"
-        uses: actions/cache@v3.3.2
-        id: nix-cache
-        with:
-          path: /tmp/nixcache
-          key: "cache-nix-store"
-      - name: "Import Nix store cache"
-        if: "steps.nix-cache.outputs.cache-hit == 'true'"
-        run: "nix-store --import < /tmp/nixcache"
       - name: Prepare cachix
         uses: https://github.com/cachix/cachix-action@v12
         with:
@@ -24,6 +35,3 @@ jobs:
       - name: Run flake checks
         run: |
           nix --print-build-logs --verbose --accept-flake-config flake check
-      - name: "Export Nix store cache"
-        if: "steps.nix-cache.outputs.cache-hit != 'true'"
-        run: "nix-store --export $(find /nix/store -maxdepth 1 -name '*-*') > /tmp/nixcache"