build(deps): bump cachix/install-nix-action from v12 to v13

dependabot[bot] · web-flow · commit 67d909322ac2 · 2021-04-05T05:21:35.000Z
Bumps [cachix/install-nix-action](https://github.com/cachix/install-nix-action) from v12 to v13. - [Release notes](https://github.com/cachix/install-nix-action/releases) - [Commits](cachix/install-nix-action@v12...8d6d5e9) Signed-off-by: dependabot[bot] <support@github.com>
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
@@ -9,6 +9,6 @@ jobs:
     - uses: actions/checkout@v2
       with:
         fetch-depth: 0
-    - uses: cachix/install-nix-action@v12
+    - uses: cachix/install-nix-action@v13
     #- run: nix flake check
     - run: nix-build -A checks.x86_64-linux.build -A checks.x86_64-linux.validate-openapi
