Add script to cancel all CI runs

Added `scripts/cancel-all-ci-runs.sh` to allow users to cancel all in-progress and queued GitHub Actions runs.
This script requires the GitHub CLI (`gh`) to be installed and authenticated.
It uses batch cancellation (`xargs`) and an increased limit (1000) for efficiency and coverage.

scripts/cancel-all-ci-runs.sh

@@ -0,0 +1,31 @@
+#!/bin/bash
+
+# Check if gh is installed
+if ! command -v gh &> /dev/null
+then
+    echo "GitHub CLI (gh) could not be found. Please install it and authenticate (gh auth login) to use this script."
+    exit 1
+fi
+
+echo "Fetching active runs..."
+
+# Function to cancel runs by status
+cancel_runs() {
+    local status=$1
+    echo "Cancelling $status runs..."
+    # Use --limit 1000 to capture up to 1000 runs (default is 30)
+    ids=$(gh run list --status "$status" --limit 1000 --json databaseId -q '.[].databaseId')
+
+    if [ -z "$ids" ]; then
+        echo "No $status runs found."
+    else
+        # Pass IDs to xargs to batch cancel commands
+        # gh run cancel accepts multiple arguments
+        echo "$ids" | xargs gh run cancel
+    fi
+}
+
+cancel_runs "in_progress"
+cancel_runs "queued"
+
+echo "Done."