chore(deps): update dependency sentry-sdk to v2.21.0

Author: renovate[bot]

requirements/base.txt

@@ -9,7 +9,7 @@ django-cloudflare-push==0.2.2
 django_csp==3.8
 redis==5.2.0
 requests==2.32.3
-sentry-sdk[django]==2.19.0
+sentry-sdk[django]==2.21.0
 urllib3==2.2.3
 wagtail==6.3.1
 whitenoise==6.8.2