ci: hydra -> github runner

.github/workflows/nix.yml

@@ -0,0 +1,15 @@
+on:
+  push:
+
+jobs:
+  nix:
+    name: Nix
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v3
+      - uses: DeterminateSystems/nix-installer-action@v4
+        with:
+          github-token: ${{ secrets.NIX_GITHUB_TOKEN }}
+      - uses: DeterminateSystems/magic-nix-cache-action@main
+      - name: Run `nix flake check`
+        run: nix flake check -L

flake.nix

@@ -4,13 +4,13 @@
     nixpkgs.follows = "fstar-flake/nixpkgs";
 
     comparse-flake = {
-      url = "git+ssh://git@github.com/TWal/comparse.git";
+      url = "github:TWal/comparse";
       inputs.nixpkgs.follows = "nixpkgs";
       inputs.fstar-flake.follows = "fstar-flake";
     };
 
     dolev-yao-star-src = {
-      url = "git+ssh://git@github.com/prosecco/dolev-yao-star.git";
+      url = "github:prosecco/dolev-yao-star";
       flake = false;
     };
   };
@@ -38,9 +38,9 @@
       ++ (fstar.buildInputs);
     };
     defaultPackage.${system} = mls-star;
-    hydraJobs = {
-      mls-build.${system} = mls-star;
-      mls-tests.${system} = mls-star.tests;
+    checks.${system} = {
+      mls-build = mls-star;
+      mls-tests = mls-star.tests;
     };
   };
 }