CI: Update and cleanup next-stats-action, force using pnpm 10.33.0 (#92475)
This should fix the stats action: We were checking out Next.js 16.2.2, and that doesn't support the `--out` flag for `pnpm pack`. Let's just force pnpm 10.33.0 here for now.
While we're here, I made some other updates and improvements:
- Update dockerfile to use Ubuntu 24.04
- Update dockerfile to use corepack 0.34.6
- Fix an issue where `pnpm install`ing outside of the docker container could break the docker container build (use `--exclude=node_modules`)
- Avoid using a shell with string interpolation (potential escaping issues) for `cd`ing, just set `cwd`.