ci: update cache-nix-action to use newly fixed cache and remove old git config

.forgejo/workflows/ci.yml

@@ -20,15 +20,14 @@ jobs:
           nix-channel --add https://nixos.org/channels/nixos-unstable nixpkgs
           nix-channel --update
       - name: restore and save nix store
-        uses: https://github.com/nix-community/cache-nix-action@v6.1.3
+        uses: https://github.com/nix-community/cache-nix-action@v7
         with:
           primary-key: nix-${{ runner.os }}-${{ hashFiles('**/*.nix', '**/flake.lock') }}
           restore-prefixes-first-match: nix-${{ runner.os }}-
           gc-max-store-size-linux: 1G
           purge: true
+          purge-last-accessed: "P1W"
           purge-prefixes: nix-${{ runner.os }}-
-          purge-created: 0
-          purge-last-accessed: 0
           purge-primary-key: never
       - name: set up nix-community cachix
         uses: https://github.com/cachix/cachix-action@v16
@@ -50,11 +49,6 @@ jobs:
           KEYID=$(gpg --list-secret-keys --with-colons | awk -F: '/^sec/{print $5;exit}')
           git config --global user.signingkey "$KEYID"
           git config --global commit.gpgsign true
-      - name: configure git for slow server
-        run: |
-          git config --global http.version HTTP/1.1
-          git config --global http.lowSpeedLimit 100
-          git config --global http.lowSpeedTime 600
       - name: run nix fmt
         run: nix fmt
       - name: check for changes