Update base image in Dockerfiles from alpine:latest to alpine:3.20

[catatsuy]

This pull request includes updates to the bench Dockerfiles to ensure compatibility with a specific version of the Alpine Linux base image. The most important changes are as follows:

Updates to Alpine Linux version:

• bench/Dockerfile: Changed the base image from alpine:latest to alpine:3.20 to ensure consistent build environments.
• bench/Dockerfile-payment: Updated the base image from alpine:latest to alpine:3.20 to align with the main Dockerfile and maintain consistency.
• bench/Dockerfile-shipment: Modified the base image from alpine:latest to alpine:3.20 to match the other Dockerfiles and ensure compatibility.