try out existing nix container made for gitea actions

.forgejo/workflows/ci.yaml

@@ -10,13 +10,13 @@ on:
 
 jobs:
   check-pre-commit:
-    runs-on: nixos
+    runs-on: icewind1991/nix-runner
     steps:
       - uses: actions/checkout@v4
       - run: nix-build -A tests
 
   check-data-model:
-    runs-on: nixos
+    runs-on: icewind1991/nix-runner
     steps:
       - uses: actions/checkout@v4
       - run: nix-shell --run 'nix-unit ./deployment/data-model-test.nix'
@@ -28,31 +28,31 @@ jobs:
       - run: nix build .#checks.x86_64-linux.test-mastodon-service -L
 
   check-peertube:
-    runs-on: nixos
+    runs-on: icewind1991/nix-runner
     steps:
       - uses: actions/checkout@v4
       - run: nix build .#checks.x86_64-linux.test-peertube-service -L
 
   check-panel:
-    runs-on: nixos
+    runs-on: icewind1991/nix-runner
     steps:
       - uses: actions/checkout@v4
       - run: nix-build -A tests.panel
 
   check-deployment-basic:
-    runs-on: nixos
+    runs-on: icewind1991/nix-runner
     steps:
       - uses: actions/checkout@v4
       - run: nix build .#checks.x86_64-linux.deployment-basic -L
 
   check-deployment-cli:
-    runs-on: nixos
+    runs-on: icewind1991/nix-runner
     steps:
       - uses: actions/checkout@v4
       - run: nix build .#checks.x86_64-linux.deployment-cli -L
 
   check-deployment-panel:
-    runs-on: nixos
+    runs-on: icewind1991/nix-runner
     steps:
       - uses: actions/checkout@v4
       - run: nix build .#checks.x86_64-linux.deployment-panel -L

.forgejo/workflows/update.yaml

@@ -8,7 +8,7 @@ on:
 
 jobs:
   lockfile:
-    runs-on: native
+    runs-on: icewind1991/nix-runner
     steps:
       - name: Checkout repository
         uses: actions/checkout@v4