Update Benchpark container

[pearce8]

• Update container to have newer Python and faster builds for upcoming tutorials
• Learn about Agentic capabilities for Containers, and what we might want to adapt from https://sc-tutorial.supercontainers.org (Sameer, Adam gave the tutorial at ISC'26)
• Try to have this ready for the PACT tutorial in October
• Waiting on convergence with fluxtainer @nhanford will help
• Possibly set up so can use Google Cloud instances in the future