docs: upgrade mkdocs-material and cleanup requirements.txt.

requirements.txt

@@ -1,44 +1,3 @@
-babel==2.17.0
-backrefs==5.8
-cairocffi==1.7.1
-CairoSVG==2.7.1
-certifi==2025.1.31
-cffi==1.17.1
-charset-normalizer==3.4.1
-click==8.1.8
-colorama==0.4.6
-cssselect2==0.8.0
-defusedxml==0.7.1
-ghp-import==2.1.0
-gitdb==4.0.12
-GitPython==3.1.44
-idna==3.10
-Jinja2==3.1.6
-Markdown==3.7
-MarkupSafe==3.0.2
-mergedeep==1.3.4
-mkdocs==1.6.1
-mkdocs-get-deps==0.2.0
+mkdocs-material==9.6.17
+mkdocs-git-revision-date-localized-plugin==1.4.7
 mkdocs-git-committers-plugin-2==2.5.0
-mkdocs-git-revision-date-localized-plugin==1.4.1
-mkdocs-material==9.6.8
-mkdocs-material-extensions==1.3.1
-packaging==24.2
-paginate==0.5.7
-pathspec==0.12.1
-pillow==10.4.0
-platformdirs==4.3.6
-pycparser==2.22
-Pygments==2.19.1
-pymdown-extensions==10.14.3
-python-dateutil==2.9.0.post0
-pytz==2025.1
-PyYAML==6.0.2
-pyyaml_env_tag==0.1
-requests==2.32.3
-six==1.17.0
-smmap==5.0.2
-tinycss2==1.4.0
-urllib3==2.3.0
-watchdog==6.0.0
-webencodings==0.5.1