ci: build c.delta.chat docs with nix

scripts/concourse/docs_wheels.yml

@@ -15,55 +15,6 @@ resources:
       tag_filter: "v*"
 
 jobs:
-  - name: doxygen
-    plan:
-      - get: deltachat-core-rust
-        trigger: true
-
-      # Build Doxygen documentation
-      - task: build-doxygen
-        config:
-          inputs:
-            - name: deltachat-core-rust
-          outputs:
-            - name: c-docs
-          image_resource:
-            source:
-              repository: alpine
-            type: registry-image
-          platform: linux
-          run:
-            path: sh
-            args:
-              - -ec
-              - |
-                apk add --no-cache doxygen git
-                cd deltachat-core-rust
-                scripts/run-doxygen.sh
-                cd ..
-                cp -av deltachat-core-rust/deltachat-ffi/html deltachat-core-rust/deltachat-ffi/xml c-docs/
-
-      - task: upload-c-docs
-        config:
-          inputs:
-            - name: c-docs
-          image_resource:
-            type: registry-image
-            source:
-              repository: alpine
-          platform: linux
-          run:
-            path: sh
-            args:
-              - -ec
-              - |
-                apk add --no-cache rsync openssh-client
-                mkdir -p ~/.ssh
-                chmod 700 ~/.ssh
-                echo "(("c.delta.chat".private_key))" > ~/.ssh/id_ed25519
-                chmod 600 ~/.ssh/id_ed25519
-                rsync -e "ssh -o StrictHostKeyChecking=no" -avz --delete c-docs/html/ delta@c.delta.chat:build-c/master
-
   - name: python-x86_64
     plan:
       - get: deltachat-core-rust