Merge pull request #2076 from CentreForDigitalHumanities/dependabot/pip/backend/idna-3.15

Bump idna from 3.10 to 3.15 in /backend

Author: lukavdplas

backend/requirements.txt

@@ -96,7 +96,7 @@ humanize==4.13.0
     # via flower
 ianalyzer-readers==0.4.0
     # via -r requirements.in
-idna==3.10
+idna==3.15
     # via requests
 iniconfig==2.1.0
     # via pytest