When attempting to install curl inside the docker image, a version conflict between curl and libcurl arises which causes all curl requests to fail with An unknown option was passed. Suggesting to either remove libcurl from the image or use a base image that does not have that issue.
$ docker run -it --entrypoint /bin/sh plugins/hugo
/ # apk add --no-cache curl > /dev/null
/ # curl https://gohugo.io/
curl: (48) An unknown option was passed in to libcurl
See go-gitea/gitea#22203 for more details.