Bump pillow from 10.2.0 to 10.3.0 in /app/backend

Bumps [pillow](https://github.com/python-pillow/Pillow) from 10.2.0 to 10.3.0.
- [Release notes](https://github.com/python-pillow/Pillow/releases)
- [Changelog](https://github.com/python-pillow/Pillow/blob/main/CHANGES.rst)
- [Commits](python-pillow/Pillow@10.2.0...10.3.0)

---
updated-dependencies:
- dependency-name: pillow
  dependency-type: direct:production
...

Signed-off-by: dependabot[bot] <[email protected]>

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
@@ -262,7 +264,7 @@ pandas==2.2.0
     # via openai
 pandas-stubs==2.2.0.240218
     # via openai
-pillow==10.2.0
+pillow==10.3.0
     # via -r requirements.in
 portalocker==2.8.2
     # via msal-extensions
@@ -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