Add nccl_version to the source-checkout torch_info fallback (#8383)

Running the unit tests from a source checkout — one that was not `pip
install`ed, so
`git_version_info_installed.py` does not exist — fails before any test
body runs:

```
FAILED unit/runtime/zero/test_zero_tensor_fragment.py::TestTensorFragmentSet::test_zero_fragments[none-1-local-dtype0]
    - KeyError: 'nccl_version'
```

`setup.py:292` writes five keys:

```python
torch_info = {
    "version": torch_version,
    "bf16_support": bf16_support,
    "cuda_version": cuda_version,
    "nccl_version": nccl_version,
    "hip_version": hip_version,
}
```

and the fallback in `deepspeed/git_version_info.py:22` lists three:

```python
torch_info = {'version': "0.0", "cuda_version": "0.0", "hip_version": "0.0"}
```

`tests/unit/util.py` reads `nccl_version` on the way into
`bf16_required_version_check`:

```python
if torch_info['nccl_version'] == '0.0':
    # Use runtime NCCL version if available
```

The `"0.0"` is a sentinel — the reader's own comment says so, and
`version`, `cuda_version` and
`hip_version` all carry it for exactly that reason. `nccl_version` was
left out, so instead of
taking the runtime-detection branch the lookup raises.

## The change

Add the missing key with the same sentinel the other three use, so the
reader takes the fallback
it was written to take.

Not adding `bf16_support`, the other key `setup.py` writes and this dict
omits: nothing reads it
off `torch_info` today (`get_accelerator().is_bf16_supported()` is used
instead), and there is no
established sentinel for a bool the way `"0.0"` is for a version. Happy
to add it if you would
rather the two dicts match key-for-key.

## Verification

Reproduced on both a CPU checkout and 2×H100:

```
# upstream/master, source checkout
>>> from unit.util import bf16_required_version_check; bf16_required_version_check()
KeyError: 'nccl_version'

# this branch
>>> bf16_required_version_check()
False        # no CUDA on that box, which is the correct answer
```

On 2 GPUs, `unit/runtime/zero/test_zero_tensor_fragment.py`:

```
master        19 failures, all  KeyError: 'nccl_version'
this branch    0 occurrences of nccl_version anywhere in the log
```

The failures that remain in my environment are all `Unable to JIT load
the {cpu_adam,fused_adam}
op due to ninja not being installed` — a missing build tool on that box,
unrelated to this
change and present identically before and after.

```
yapf==0.40.0 --diff    (no diff)
```

---------

Signed-off-by: alanhuangyoo <alanhuangyoo@gmail.com>
Co-authored-by: Ma, Guokai <guokai.ma@gmail.com>

Author: alanhuangyoo

deepspeed/git_version_info.py

@@ -19,7 +19,9 @@
     from .ops.op_builder.all_ops import ALL_OPS
     installed_ops = dict.fromkeys(ALL_OPS.keys(), False)
     accelerator_name = ""
-    torch_info = {'version': "0.0", "cuda_version": "0.0", "hip_version": "0.0"}
+    # Keys must match what setup.py writes into git_version_info_installed, and "0.0" is the
+    # sentinel readers check to fall back to runtime detection.
+    torch_info = {'version': "0.0", "cuda_version": "0.0", "nccl_version": "0.0", "hip_version": "0.0"}
 
 # compatible_ops list is recreated for each launch
 from .ops.op_builder.all_ops import ALL_OPS