Bump pygments from 2.17.2 to 2.20.0 in /wrap/pybind11/docs

Bumps [pygments](https://github.com/pygments/pygments) from 2.17.2 to 2.20.0.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.17.2...2.20.0)

---
updated-dependencies:
- dependency-name: pygments
  dependency-version: 2.20.0
  dependency-type: indirect
...

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

Author: dependabot[bot]

wrap/pybind11/docs/requirements.txt

@@ -23,8 +23,6 @@ idna==3.7
     # via requests
 imagesize==1.4.1
     # via sphinx
-importlib-metadata==8.7.0
-    # via sphinx
 jinja2==3.1.6
     # via
     #   myst-parser
@@ -43,7 +41,7 @@ myst-parser==3.0.1
     # via -r requirements.in
 packaging==24.0
     # via sphinx
-pygments==2.17.2
+pygments==2.20.0
     # via
     #   furo
     #   sphinx
@@ -87,5 +85,3 @@ sphinxcontrib-svg2pdfconverter==1.2.2
     # via -r requirements.in
 urllib3==2.5.0
     # via requests
-zipp==3.23.0
-    # via importlib-metadata