Update requirements.txt

Jinja 3.1 breaks things
mkdocs/mkdocs#2794
https://github.com/squidfunk/mkdocs-material/releases/tag/8.2.7

requirements.txt

@@ -7,4 +7,4 @@ mkdocs-material-extensions>=1.0.3
 mkdocs-macros-plugin>=0.6.0
 mkdocs-minify-plugin>=0.4
 mkdocs-redirects>=1.0
-Jinja2>=3.0.2  # https://github.com/squidfunk/mkdocs-material/issues/3356
+Jinja2>=3.0.2,<3.1  # https://github.com/squidfunk/mkdocs-material/issues/3356