move load calls, rename test for better readibility (#601)

### Description
Makes the test_model use the converted nemo2 checkpoint for 650M, and
better renames the test that requires the Nemo1 checkpoint

### Type of changes
<!-- Mark the relevant option with an [x] -->

- [x]  Bug fix (non-breaking change which fixes an issue)
- [ ]  New feature (non-breaking change which adds functionality)
- [x]  Refactor
- [ ]  Documentation update
- [ ]  Other (please describe):

### CI Pipeline Configuration
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- [ ]
[SKIP_CI](https://github.com/NVIDIA/bionemo-framework/blob/main/docs/docs/user-guide/contributing/contributing.md#skip_ci)
- Skip all continuous integration tests
- [ ]
[INCLUDE_NOTEBOOKS_TESTS](https://github.com/NVIDIA/bionemo-framework/blob/main/docs/docs/user-guide/contributing/contributing.md#include_notebooks_tests)
- Execute notebook validation tests in pytest

> [!NOTE]
> By default, the notebooks validation tests are skipped unless
explicitly enabled.

### Usage
<!--- How does a user interact with the changed code -->
```python
TODO: Add code snippet
```

### Pre-submit Checklist
<!--- Ensure all items are completed before submitting -->

 - [x] I have tested these changes locally
 - [ ] I have updated the documentation accordingly
 - [x] I have added/updated tests as needed
 - [ ] All existing tests pass successfully

Signed-off-by: Peter St. John <[email protected]>

sub-packages/bionemo-esm2/tests/bionemo/esm2/model/test_model.py

@@ -17,7 +17,6 @@
 import io
 import tarfile
 from copy import deepcopy
-from pathlib import Path
 from typing import List, Tuple
 from unittest import mock
 
@@ -39,9 +38,6 @@
 from bionemo.testing import megatron_parallel_state_utils
 
 
-nemo1_checkpoint_path: Path = load("esm2/nv_650m:1.0")
-
-
 def reduce_hiddens(hiddens: Tensor, attention_mask: Tensor) -> Tensor:
     """reduce last layer's hidden values to embeddings
 
@@ -72,7 +68,7 @@ def esm2_config() -> ESM2Config:
 @pytest.fixture(scope="module")
 def esm2_650M_config_w_ckpt() -> ESM2Config:
     with megatron_parallel_state_utils.distributed_model_parallel_state():
-        yield ESM2Config(nemo1_ckpt_path=nemo1_checkpoint_path)
+        yield ESM2Config(initial_ckpt_path=load("esm2/650m:2.0"))
 
 
 @pytest.fixture(scope="module")
@@ -141,7 +137,7 @@ def test_esm2_model_initialized(esm2_model):
 
 
 def test_esm2_650m_checkpoint(esm2_model):
-    with tarfile.open(nemo1_checkpoint_path, "r") as ckpt, torch.no_grad():
+    with tarfile.open(load("esm2/nv_650m:1.0"), "r") as ckpt, torch.no_grad():
         ckpt_file = ckpt.extractfile("./model_weights.ckpt")
 
         old_state_dict = torch.load(ckpt_file)