Limit devshells in github actions to only required packages

Author: carbolymer

.github/workflows/actionlint.yml

@@ -20,6 +20,8 @@ jobs:
             accept-flake-config = true
       # Make the Nix environment available to next steps
       - uses: rrbutani/use-nix-shell-action@v1
+        with:
+          flakes: nixpkgs#shellcheck,nixpkgs#actionlint
 
       - name: actionlint
         run: |

.github/workflows/check-changelog.yml

@@ -39,9 +39,11 @@ jobs:
           extra_nix_config: |
             accept-flake-config = true
 
-      - name: Check scriv fragments are correct
+      - uses: rrbutani/use-nix-shell-action@v1
         if: steps.filter.outputs.cardano == 'true'
-        uses: rrbutani/use-nix-shell-action@v1
         with:
-          script: cd cardano-testnet && scriv collect --version "CI-CHECK" --keep
+          flakes: nixpkgs#scriv
+      - name: Check scriv fragments are correct
+        if: steps.filter.outputs.cardano == 'true'
+        run: cd cardano-testnet && scriv collect --version "CI-CHECK" --keep
 

.github/workflows/shellcheck.yml

@@ -20,8 +20,9 @@ jobs:
         with:
           extra_nix_config: |
             accept-flake-config = true
-      # Make the Nix environment available to next steps
       - uses: rrbutani/use-nix-shell-action@v1
+        with:
+          flakes: nixpkgs#shellcheck
       - name: shellcheck
         run: |
           for file in $(git ls-files "*.sh")