Bump cohere from 5.14.0 to 5.15.0

Bumps cohere from 5.14.0 to 5.15.0.

---
updated-dependencies:
- dependency-name: cohere
  dependency-version: 5.15.0
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

poetry.lock

@@ -14,7 +14,7 @@ matplotlib = "^3.10.1"
 torch = "^2.5.1"
 transformers = "<=4.51.3"
 wandb = "^0.19.10"
-cohere = "^5.14.0"
+cohere = "^5.15.0"
 onnx = "^1.17.0"
 onnxruntime = "^1.21.1"
 ray = {extras = ["data", "train", "tune"], version = "^2.40.0"}