fix: Update http_spec baggage assertion to include sentry-org_id

The test DSN uses o447951.ingest.sentry.io, so the new org_id
propagation correctly adds sentry-org_id=447951 to baggage.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

Author: 2 people

sentry-ruby/spec/sentry/net/http_spec.rb

@@ -156,7 +156,8 @@
         "sentry-sample_rand=#{Sentry::Utils::SampleRand.format(transaction.sample_rand)},"\
         "sentry-sampled=true,"\
         "sentry-environment=development,"\
-        "sentry-public_key=foobarbaz"
+        "sentry-public_key=foobarbaz,"\
+        "sentry-org_id=447951"
       )
     end