Merge pull request #96 from ecmwf/dependabot/pip/ci/jinja2-3.1.4

Bump jinja2 from 2.10.1 to 3.1.4 in /ci

Author: shahramn

ci/requirements-docs.txt

@@ -18,9 +18,9 @@ idna==2.8
     # via requests
 imagesize==1.1.0
     # via sphinx
-jinja2==2.10.1
+jinja2==3.1.4
     # via sphinx
-markupsafe==1.1.1
+markupsafe==2.1.5
     # via jinja2
 packaging==19.0
     # via sphinx