Try curl timeouts, as the runner connection appears instable.

.gitlab-ci.yml

@@ -19,10 +19,10 @@ build-job:
     - python3 setup.py sdist bdist_wheel
     - apt-get install -y -qq curl --fix-missing
     # get the current package id
-    - 'export ID=$(curl --request GET --header "PRIVATE-TOKEN: ${API_ACCES_TOKEN}" "https://git.gfz-potsdam.de/api/v4/projects/${CI_PROJECT_ID}/packages" | grep -P "(?<=.id.:)(\\d+)" -o  | head -1)' 
+    - 'export ID=$(curl --max-time 900 --connect-timeout 120 --request GET --header "PRIVATE-TOKEN: ${API_ACCES_TOKEN}" "https://git.gfz-potsdam.de/api/v4/projects/${CI_PROJECT_ID}/packages" | grep -P "(?<=.id.:)(\\d+)" -o  | head -1)' 
     # remove the package, as we want a new build even if the version number did not change
     - 'echo $ID'
-    - 'curl --request DELETE --header "PRIVATE-TOKEN: ${API_ACCES_TOKEN}" "https://git.gfz-potsdam.de/api/v4/projects/${CI_PROJECT_ID}/packages/$ID"'
+    - 'curl --max-time 900 --connect-timeout 120 --request DELETE --header "PRIVATE-TOKEN: ${API_ACCES_TOKEN}" "https://git.gfz-potsdam.de/api/v4/projects/${CI_PROJECT_ID}/packages/$ID"'
     # upload
     - TWINE_PASSWORD=${CI_JOB_TOKEN} TWINE_USERNAME=gitlab-ci-token python3 -m twine upload --repository-url https://git.gfz-potsdam.de/api/v4/projects/${CI_PROJECT_ID}/packages/pypi dist/* --verbose
   only: