[infra] repotests needs some serious rework and compute

[prabhu]

• repo tests is too slow and inadequate
• We are only testing against the latest node 23.x and not against a matrix of node, deno, bun combinations.
• For language-specific tests, we aren't testing against multiple versions of the particular language (JDK, Go, etc) and package managers.

For blint, we just bought a new server with "AMD Ryzen Threadripper 7960X 24 Core CPU" and 128GB RAM (🎉). cdxgen already use a couple of Mac Minis. Perhaps we need multiple mini PCs like Beelink SER8, rather than a single beefier server?

[prabhu]

Beelink SER8 is operational now. Working on this PR to move some work to this new machine. Btw, this is mini pc is just brilliant! With 8 GB VRAM, even cdx1 runs with decent performance.