ref(profiling): Record flamegraph endpoint dataSource param (#112597)

Need to make sure that requests with the `dataSource` set to
`transactions` taper off as we remove frontend callers that use it.

Author: mjq

src/sentry/api/endpoints/organization_profiling_profiles.py

@@ -1,3 +1,4 @@
+import sentry_sdk
 from django.http import HttpResponse
 from rest_framework import serializers
 from rest_framework.exceptions import ParseError
@@ -77,6 +78,8 @@ def get(self, request: Request, organization: Organization) -> HttpResponse:
             return Response(serializer.errors, status=400)
         serialized = serializer.validated_data
 
+        sentry_sdk.set_tag("query.dataSource", serialized["dataSource"])
+
         with handle_query_errors():
             executor = FlamegraphExecutor(
                 request=request,