refactor(action): update description and improve step names in install-nix action

.github/actions/install-nix/action.yml

@@ -1,27 +1,16 @@
 name: install-nix
-description: Composite action to checkout the repo and install Nix with flakes enabled
+description: Install Nix with flakes enabled and pre-warm the repository's flake devShell
 runs:
   using: composite
   steps:
-    - name: Install Nix
+    - name: Install Nix (with flakes)
       uses: cachix/install-nix-action@v31
       with:
         extra_nix_config: |
           experimental-features = nix-command flakes
-    - name: Prewarm flake devShell
+    - name: Pre-warm flake devShell
       run: |
-        # use the flake devShell defined in ./flake.nix to fetch deps
-        nix develop --command true
-      shell: bash
-
-    - name: Install Nix
-      uses: cachix/install-nix-action@v31
-      with:
-        extra_nix_config: |
-          experimental-features = nix-command flakes
-
-    - name: Prewarm flake devShell
-      run: |
-        # use the flake devShell defined in ./flake.nix to fetch deps
+        # Use the repository's `flake.nix` devShell to fetch dependencies.
+        # This speeds up later `nix develop` invocations in workflow steps.
         nix develop --command true
       shell: bash

.github/workflows/check.yml

@@ -11,29 +11,29 @@ jobs:
   lint:
     runs-on: ubuntu-latest
     steps:
-      - name: Checkout
+      - name: Checkout repository
         uses: actions/checkout@v5
 
-      - name: Setup checkout + Nix
+      - name: Install Nix and pre-warm flake devShell
         uses: ./.github/actions/install-nix
 
       - name: Run pre-commit from flake devShell
         run: |
-          # use the flake devShell defined in ./flake.nix (x86_64 runner)
+          # Use the flake devShell defined in ./flake.nix (x86_64 runner)
           nix develop --command pre-commit run --all-files
         shell: bash
 
   build:
     runs-on: ubuntu-latest
     steps:
-      - name: Checkout
+      - name: Checkout repository
         uses: actions/checkout@v5
 
-      - name: Setup checkout + Nix
+      - name: Install Nix and pre-warm flake devShell
         uses: ./.github/actions/install-nix
 
       - name: Run build from flake devShell
         run: |
-          # use the flake devShell defined in ./flake.nix (x86_64 runner)
+          # Use the flake devShell defined in ./flake.nix (x86_64 runner)
           nix develop --command invoke build
         shell: bash