build: bump pypandoc from 1.14 to 1.15 in the documentation group

Bumps the documentation group with 1 update: [pypandoc](https://github.com/JessicaTegner/pypandoc).


Updates `pypandoc` from 1.14 to 1.15
- [Release notes](https://github.com/JessicaTegner/pypandoc/releases)
- [Changelog](https://github.com/JessicaTegner/pypandoc/blob/master/release.md)
- [Commits](JessicaTegner/pypandoc@v1.14...v1.15)

---
updated-dependencies:
- dependency-name: pypandoc
  dependency-type: direct:production
  update-type: version-update:semver-minor
  dependency-group: documentation
...

Signed-off-by: dependabot[bot] <[email protected]>

pyproject.toml

@@ -88,7 +88,7 @@ doc = [
     "pandas==2.2.3",
     "plotly==5.24.1",
     "pyiges[full]==0.3.1",
-    "pypandoc==1.14",
+    "pypandoc==1.15",
     "pytest-sphinx==0.6.3",
     "pythreejs==2.4.2",
     "sphinx-autobuild==2024.10.3",