Update model info json (#725)

Fixes # .

### Description
A few sentences describing the changes proposed in this pull request.

### Status
**Ready/Work in progress/Hold**

### Please ensure all the checkboxes:
<!--- Put an `x` in all the boxes that apply, and remove the not
applicable items -->
- [x] Codeformat tests passed locally by running `./runtests.sh
--codeformat`.
- [ ] In-line docstrings updated.
- [ ] Update `version` and `changelog` in `metadata.json` if changing an
existing bundle.
- [ ] Please ensure the naming rules in config files meet our
requirements (please refer to: `CONTRIBUTING.md`).
- [ ] Ensure versions of packages such as `monai`, `pytorch` and `numpy`
are correct in `metadata.json`.
- [ ] Descriptions should be consistent with the content, such as
`eval_metrics` of the provided weights and TorchScript modules.
- [ ] Files larger than 25MB are excluded and replaced by providing
download links in `large_file.yml`.
- [ ] Avoid using path that contains personal information within config
files (such as use `/home/your_name/` for `"bundle_root"`).

---------

Signed-off-by: Yiheng Wang <[email protected]>
Signed-off-by: Yiheng Wang <[email protected]>
Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

models/model_info.json

@@ -1800,7 +1800,15 @@
         "source": "https://api.ngc.nvidia.com/v2/models/nvidia/monaihosting/maisi_ct_generative/versions/0.4.6/files/maisi_ct_generative_v0.4.6.zip"
     },
     "cxr_image_synthesis_latent_diffusion_model_v1.0.0": {
-        "checksum": "b3322c67da54489df18a9cf54c8c0a2fbb0fa19d",
+        "checksum": "47b66d3325b582ed23f6583e7f95982424914185",
         "source": "https://api.ngc.nvidia.com/v2/models/nvidia/monaihosting/cxr_image_synthesis_latent_diffusion_model/versions/1.0.0/files/cxr_image_synthesis_latent_diffusion_model_v1.0.0.zip"
+    },
+    "mednist_ddpm_v1.0.0": {
+        "checksum": "e01b9d8b5bfe961ee4b3cfc54bf0574954a84569",
+        "source": "https://api.ngc.nvidia.com/v2/models/nvidia/monaihosting/mednist_ddpm/versions/1.0.0/files/mednist_ddpm_v1.0.0.zip"
+    },
+    "brain_image_synthesis_latent_diffusion_model_v1.0.0": {
+        "checksum": "6c39a58e1645c7fec8e433cf21eb39b35c1a900a",
+        "source": "https://api.ngc.nvidia.com/v2/models/nvidia/monaihosting/brain_image_synthesis_latent_diffusion_model/versions/1.0.0/files/brain_image_synthesis_latent_diffusion_model_v1.0.0.zip"
     }
 }