ci: do not use GitHub cache

Signed-off-by: Roman Volosatovs <[email protected]>

Author: rvolosatovs

.github/actions/install-nix/action.yml

@@ -11,7 +11,6 @@ runs:
     with:
       extra-conf: |
         accept-flake-config = true
-  - uses: DeterminateSystems/magic-nix-cache-action@v13
   - uses: cachix/cachix-action@v16
     continue-on-error: true
     with: