ci: use stable versions of actions

Author: ryanccn

.github/workflows/nix.yml

@@ -27,7 +27,7 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Install Nix
-        uses: DeterminateSystems/nix-installer-action@main
+        uses: DeterminateSystems/nix-installer-action@v4
 
       - name: Setup Attic cache
         uses: ryanccn/attic-action@v0
@@ -41,4 +41,4 @@ jobs:
         run: nix flake check
 
       - name: Build
-        run: nix build --accept-flake-config ".#nyoom"
+        run: nix build ".#nyoom"

.github/workflows/release.yml

@@ -35,8 +35,8 @@ jobs:
         uses: actions/checkout@v4
 
       - name: Install Nix
-        uses: DeterminateSystems/nix-installer-action@main
+        uses: DeterminateSystems/nix-installer-action@v4
       - name: Push to FlakeHub
-        uses: DeterminateSystems/flakehub-push@main
+        uses: DeterminateSystems/flakehub-push@v3
         with:
           visibility: public