README: upgrade flake example

tested with https://github.com/Mic92/dotfiles/runs/1491667409?check_suite_focus=true
cachix · Dec 3, 2020 · fa64b9e · fa64b9e
1 parent ef43243
commit fa64b9e
Showing 1 changed file with 1 addition and 1 deletion.
diff --git a/README.md b/README.md
@@ -55,7 +55,7 @@ jobs:
       with:
           # Nix Flakes doesn't work on shallow clones
           fetch-depth: 0
-    - uses: cachix/install-nix-action@v11
+    - uses: cachix/install-nix-action@v12
       with:
         install_url: https://github.com/numtide/nix-flakes-installer/releases/download/nix-3.0pre20200820_4d77513/install
         extra_nix_config: |