Bump idna from 3.6 to 3.7 in /app/backend

Bumps [idna](https://github.com/kjd/idna) from 3.6 to 3.7.
- [Release notes](https://github.com/kjd/idna/releases)
- [Changelog](https://github.com/kjd/idna/blob/master/HISTORY.rst)
- [Commits](kjd/idna@v3.6...v3.7)

---
updated-dependencies:
- dependency-name: idna
  dependency-type: indirect
...

Signed-off-by: dependabot[bot] <support@github.com>

app/backend/requirements.txt

@@ -21,7 +21,9 @@ asgiref==3.7.2
 attrs==23.2.0
     # via aiohttp
 azure-common==1.1.28
-    # via azure-search-documents
+    # via
+    #   azure-keyvault-secrets
+    #   azure-search-documents
 azure-core==1.30.0
     # via
     #   azure-core-tracing-opentelemetry
@@ -105,7 +107,7 @@ hypercorn==0.16.0
     # via quart
 hyperframe==6.0.1
     # via h2
-idna==3.6
+idna==3.7
     # via
     #   anyio
     #   httpx
@@ -279,10 +281,10 @@ pydantic==2.6.1
 pydantic-core==2.16.2
     # via pydantic
 pyjwt[crypto]==2.8.0
-    # via msal
+    # via
+    #   msal
+    #   pyjwt
 python-dateutil==2.8.2
-
-python-dotenv
     # via pandas
 python-jose[cryptography]==3.3.0
     # via -r requirements.in