ci: try to fix pushing

.github/workflows/update.yml

@@ -12,6 +12,7 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v2
+      fetch-depth: '0'
     - uses: cachix/install-nix-action@v12
       with:
         nix_path: nixpkgs=channel:nixos-unstable

ci/update-nur-search.sh

@@ -19,8 +19,6 @@ git clone \
   --single-branch \
   "https://$API_TOKEN_GITHUB@github.com/nix-community/nur-combined.git"
 
-git clone git@github.com:nix-community/nur-combined
-
 nix run '(import ./release.nix {})' -c nur index nur-combined > nur-search/data/packages.json
 
 # rebuild and publish nur-search repository

ci/update-nur.sh

@@ -26,7 +26,7 @@ else
   git commit -m "automatic update"
   # in case we are getting overtaken by a different job
   git pull --rebase origin master
-  git push git@github.com:nix-community/NUR HEAD:master
+  git push $API_TOKEN_GITHUB@github.com:nix-community/NUR HEAD:master
 fi
 
 git -C nur-combined pull --rebase origin master