This bash script deletes all the runs from a Github Actions workflow, since you can't delete a workflow from the UI

delete-workflow-runs.sh

#!/bin/bash

# Set the repository owner and name
owner="<owner>"
repo="<repo>"


# Replace <YOUR-PAT> with your actual Personal Access Token PAT
PAT="<YOUR-PAT>"

auth_curl() { curl -s -H "Authorization: Bearer $PAT" "$@"; }

# Get the workflow name from the command line argument or from user input
if [ -z "$1" ]; then
  auth_curl "https://api.github.com/repos/$owner/$repo/actions/workflows" | jq -r ".workflows[].name"
  read -rp "Enter the workflow name: " workflow_name
else
  workflow_name="$1"
fi

# Get the workflow ID using the GitHub API
workflow_id=$(auth_curl "https://api.github.com/repos/$owner/$repo/actions/workflows" | jq -r ".workflows[] | select(.name == \"$workflow_name\") | .id")
if [ -z "$workflow_id" ]; then
  echo "Workflow not found."
  exit 1
fi

# Get a list of all the workflow runs using the GitHub API
workflow_runs=$(auth_curl "https://api.github.com/repos/$owner/$repo/actions/workflows/$workflow_id/runs?per_page=100" | jq -r ".workflow_runs[] | .id")

# Loop through the workflow runs and delete them using the GitHub API
for run_id in $workflow_runs; do
  echo "Deleting run $run_id..."
  auth_curl -X DELETE "https://api.github.com/repos/$owner/$repo/actions/runs/$run_id"
done

echo "Done."