Relax requirements for textproc/py-pygments

--- requirements.txt.orig	2022-01-09 17:57:41 UTC
+++ requirements.txt
@@ -23,5 +23,5 @@ jinja2>=2.11.1
 markdown>=3.2
 mkdocs>=1.2.3
 mkdocs-material-extensions>=1.0
-pygments>=2.10
+pygments
 pymdown-extensions>=9.0