Update highsbox requirement from <=1.12.0 to <=1.13.0 (#223)

Updates the requirements on [highsbox](https://github.com/metab0t/highsbox) to permit the latest version.
- [Commits](https://github.com/metab0t/highsbox/commits)

---
updated-dependencies:
- dependency-name: highsbox
  dependency-version: 1.13.0
  dependency-type: direct:development
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

Author: dependabot[bot]

pyproject.toml

@@ -27,7 +27,7 @@ dependencies = [
 ]
 
 [project.optional-dependencies]
-highs = ["highsbox<=1.12.0"]
+highs = ["highsbox<=1.13.0"]
 ipopt = [
     "pyoptinterface[nlp]",
     "llvmlite<=0.46.0",    # Capped to prevent breaking changes in pyoptinterface. See https://github.com/metab0t/PyOptInterface/issues/56
@@ -44,7 +44,7 @@ dev = [
     "ipykernel==6.30.1",    # add support for jupyter notebooks
     # Automatically install as many solvers as possible
     # (we don't pin since we want to test against the latest)
-    "highsbox<=1.12.0",
+    "highsbox<=1.13.0",
     "pyoptinterface[nlp]",
     "numpy",               # for testing with np.nan, don't pin so that two versions of Python are possible
 ]