Show messages for builds and large downloads in non-interactive mode (#11165)

When stderr is not a tty, we currently don't show any messages for build
or large downloads, since indicatif is hidden. We can improve this by
showing a message for:

* Starting and finishing a large download (>1MB)
* Starting and finishing a build

Downloads are limited to 1MB or unknown size to keep the logs concise
and not scroll the entire terminal away for a download that finishes
almost immediately.

These messages are not captured in the tests since their order is
non-deterministic (downloads and builds race to finish).

There are no "tick" messages for large downloads yet, we could e.g. show
an update on runnning downloads every n seconds.

Part of #11121

**Test Plan**

```
$ uv venv && FORCE_COLOR=1 cargo run -q pip install numpy --no-binary :all: --no-cache 2>&1 | tee a.txt
  Using CPython 3.13.0
  Creating virtual environment at: .venv
  Activate with: source .venv/bin/activate
  Resolved 1 package in 221ms
     Building numpy==2.2.2
        Built numpy==2.2.2
  Prepared 1 package in 2m 34s
  Installed 1 package in 6ms
   + numpy==2.2.2
```


![image](https://github.com/user-attachments/assets/f4b64313-afa7-449f-9e5b-2b1b7026bef3)


```
$ uv venv && FORCE_COLOR=1 cargo run -q pip install torch --no-cache 2>&1 | tee b.txt
  Using CPython 3.13.0
  Creating virtual environment at: .venv
  Activate with: source .venv/bin/activate
  Resolved 24 packages in 648ms
  Downloading setuptools (1.2MiB)
  Downloading nvidia-cuda-cupti-cu12 (13.2MiB)
  Downloading torch (731.1MiB)
  Downloading nvidia-nvjitlink-cu12 (20.1MiB)
  Downloading nvidia-cufft-cu12 (201.7MiB)
  Downloading nvidia-cuda-nvrtc-cu12 (23.5MiB)
  Downloading nvidia-curand-cu12 (53.7MiB)
  Downloading nvidia-nccl-cu12 (179.9MiB)
  Downloading nvidia-cudnn-cu12 (634.0MiB)
  Downloading nvidia-cublas-cu12 (346.6MiB)
  Downloading sympy (5.9MiB)
  Downloading nvidia-cusparse-cu12 (197.8MiB)
  Downloading nvidia-cusparselt-cu12 (143.1MiB)
  Downloading networkx (1.6MiB)
  Downloading nvidia-cusolver-cu12 (122.0MiB)
  Downloading triton (241.4MiB)
   Downloaded setuptools
   Downloaded networkx
   Downloaded sympy
   Downloaded nvidia-cuda-cupti-cu12
   Downloaded nvidia-nvjitlink-cu12
   Downloaded nvidia-cuda-nvrtc-cu12
   Downloaded nvidia-curand-cu12
[...]
```


![image](https://github.com/user-attachments/assets/71918d94-c5c0-44ce-bea8-aaba6cd80ef7)

crates/uv-git/src/source.rs

@@ -133,7 +133,7 @@ impl GitSource {
         // Report the checkout operation to the reporter.
         if let Some(task) = task {
             if let Some(reporter) = self.reporter.as_ref() {
-                reporter.on_checkout_complete(remote.url(), short_id.as_str(), task);
+                reporter.on_checkout_complete(remote.url(), actual_rev.as_str(), task);
             }
         }