Running tests uses 50.1GB of disk space on Ubuntu

### Describe the bug

I just cloned datafusion and tried `cargo t` on my ubuntu desktop, to check things were working properly.

It crashed.

I restarted, and it seems datafusion is using 50.1GB to just run tests.

The `examples` directory seems to be the biggest culpret.


### To Reproduce

Just clone and run `cargo t` on Ubuntu (no idea if this is limited to linux).

### Expected behavior

Humm, I guess in principle this isn't a show stopper, but seems somewhat unfortunate.

If there's an easy/low impact way to reduce disk usage, it might be useful.

### Additional context

_No response_

Start by cloning DataFusion on Ubuntu and reproducing the issue with `cargo t`, then inspect disk usage with particular attention to the `examples` directory mentioned in the report. Compare which test-related artifacts consume space and verify that any reduction preserves successful test execution without the reported excessive usage.

Written by the indexing model from the issue text.