[C++][CI] ubuntu-cpp-bundled-offline is much too slow

[pitrou]

Describe the bug, including details regarding any error messages, version, and platform.

The test-ubuntu-24.04-cpp-bundled-offline Crossbow job usually takes one hour to complete:
https://github.com/ursacomputing/crossbow/actions/runs/34175056969/job/101902703505

This is because, despite sccache being configured, the S3-stored compilation cache is unavailable because the network is shut off during compilation.

In addition to that, the job compiles all dependencies from scratch.

We should find a way to have a working compilation cache during that job.

(or perhaps we can simply remove the job?)

Component(s)

Continuous Integration, C++

[pitrou]

How about moving it to apache/arrow and using apache/infrastructure-actions/stash/ instead?

I think that the offline job is needed to keep offline build workable.

BTW, should we move this issue to apache/arrow from ursacomputing/corssbow?

Originally posted by @kou in #100