Make it easier to maintain version updates

[nedtwigg]

• it would be nice if our default versions were always the latest version
• renovate opens PRs for us whenever a new version comes out, but we have to do the work to update the defaults and fix bugs if any
• Claude Code or similar can certainly do this, I would guess > 80% success rate
• it would be nice if this happened automatically rather than requiring us to do it ourselves

There are other approaches to "modernizing" our build

• #2704
• #2705

I'm not against those issues, but I don't understand the goal. I think making version upgrades easier is a problem we have. If people are trying to solve that problem, let's focus on that problem and not prematurely fixate on a specific possible solution.