actionlint: provision it in Nix shell, and use the same in CI

.github/workflows/actionlint.yml

@@ -25,11 +25,6 @@ jobs:
       # Make the Nix environment available to next steps
       - uses: rrbutani/use-nix-shell-action@v1
 
-      - name: Install actionlint
-        run: |
-          # Puts the "actionlint" binary in the working folder
-          bash <(curl https://raw.githubusercontent.com/rhysd/actionlint/main/scripts/download-actionlint.bash)
-
       - name: Run Actionlint
         run: |
           for file in $(git ls-files ".github/workflows/*.y*ml")
@@ -38,7 +33,7 @@ jobs:
             then
               echo "⚠️ $file is ignored from actionlint's verifications. Please consider fixing it."
             else
-              echo "./actionlint $file"
-              ./actionlint "$file"
+              echo "actionlint $file"
+              actionlint "$file"
             fi
           done

flake.nix

@@ -81,7 +81,7 @@
               stylish-haskell = "0.14.5.0";
             };
           # and from nixpkgs or other inputs
-          shell.nativeBuildInputs = with nixpkgs; [ gh jq yq-go shellcheck ];
+          shell.nativeBuildInputs = with nixpkgs; [ gh jq yq-go actionlint shellcheck ];
           # disable Hoogle until someone request it
           shell.withHoogle = false;
           # Skip cross compilers for the shell