chore: remove Drone test config

.drone.yml

@@ -1,45 +0,0 @@
----
-kind: pipeline
-type: docker
-name: amd64-main
-
-platform:
-  os: linux
-  arch: amd64
-
-trigger:
-  branch:
-    - main
-  event:
-    - push
-    - pull_request
-
-steps:
-  - name: build
-    image: sphinxdoc/sphinx-latexpdf:5.0.2
-    commands:
-      - apt-get update
-      - apt-get -y install texlive-lang-german rsync
-      - pip install -r requirements.txt
-      - make -j4 latexpdf
-  - name: upload
-    image: alpine
-    environment:
-      NC_USER:
-        from_secret: nextcoud_user
-      NC_PASSWORD:
-        from_secret: nextcloud_password
-    commands:
-      - apt add curl
-      - curl -X PUT -u $NC_USER:$NC_PASSWORD https://work.wtf-eg.de/remote.php/dav/files/$NC_USER/FreeFleetManagement/FFFleet%20Handbuch.pdf -T bundle/latex/rtfm-dashandbuchderfreefederatedfleetfffleetinitiative.pdf
-    when:
-      branch:
-        - main
-      event:
-        - push
-
----
-kind: signature
-hmac: 7225cd21b9a1284bba09bd0f943e5873865f176e1dca49147ea8e309421e6726
-
-...