Refactor OpenStack script to handle multiple attached volumes

The original code assumed only one volume is attached to the specified OpenStack instance. This commit modifies the script to correctly handle scenarios where multiple volumes are attached. The updated code uses an array to store all attached volumes, iterates over the array, and performs actions for each volume. This enhances the script's flexibility and ensures accurate detachment messages for all attached volumes.

Changes:
- Modified the extraction of the instance ID to handle potential changes in the output structure.
- Implemented an array to store all attached volumes.
- Added a loop to iterate over the array and print detachment messages for each volume.