chore(deps): bump pygments from 2.18.0 to 2.20.0 in /docs (#464)

Bumps [pygments](https://github.com/pygments/pygments) from 2.18.0 to 2.20.0.
- [Release notes](https://github.com/pygments/pygments/releases)
- [Changelog](https://github.com/pygments/pygments/blob/master/CHANGES)
- [Commits](pygments/pygments@2.18.0...2.20.0)

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

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

Author: dependabot[bot]

docs/requirements.txt

@@ -18,15 +18,13 @@ idna==3.7
     # via requests
 imagesize==1.4.1
     # via sphinx
-importlib-metadata==8.7.0
-    # via sphinx
 jinja2==3.1.6
     # via sphinx
 markupsafe==2.1.5
     # via jinja2
 packaging==24.1
     # via sphinx
-pygments==2.18.0
+pygments==2.20.0
     # via
     #   furo
     #   sphinx
@@ -55,9 +53,5 @@ sphinxcontrib-qthelp==1.0.8
     # via sphinx
 sphinxcontrib-serializinghtml==1.1.10
     # via sphinx
-tomli==2.2.1
-    # via sphinx
 urllib3==2.5.0
     # via requests
-zipp==3.23.0
-    # via importlib-metadata