Delete GitHub wiki revisions

gistfile1.sh

# Delete prior revisions from a GitHub wiki so that only the most-recent
# version of the content is available.

# Clone the wiki.
git clone https://github.com/[user]/[repo].wiki.git

# Remove the .git folder.
rm -rf .git

# Reconstruct the local repo with only latest content
git init
git add .
git commit -m "Initial commit"

# Push to GitHub
git remote add origin <github-uri>
git push -u --force origin master

I also had problems pushing using: git push -u --force origin master
I seems you need a personal access token to login on the command line
https://docs.github.com/en/github/authenticating-to-github/keeping-your-account-and-data-secure/creating-a-personal-access-token