fix: requirements.txt to reduce vulnerabilities

The following vulnerabilities are fixed by pinning transitive dependencies:
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-6050294
- https://snyk.io/vuln/SNYK-PYTHON-CRYPTOGRAPHY-6126975

requirements.txt

@@ -38,7 +38,7 @@ openpyxl==3.1.2
 xlrd==1.2.0
 Pillow==10.0.0  # required by django-imagekit
 psycopg2-binary==2.9.6
-cryptography==41.0.3
+cryptography==42.0.0
 python-dateutil==2.8.2
 pytz==2023.3
 redis==4.6.0