test(rails): stop the uninitialized-Sentry stub leaking into cleanup

The example stubs Sentry.initialized? to false, and RSpec tears mocks down
after the suite's after hooks run. The sentry-rails hook only clears captured
events and detaches the structured logging subscribers when Sentry reports
itself initialized, so the stub made it skip both. The subscribers stayed
attached and later examples inherited log events they never emitted, failing
whenever the order put them after this one.

Scoping the stub to the call under test lets the hook see the real state.

Co-Authored-By: Claude Opus 5 <noreply@anthropic.com>

Author: solnic

sentry-rails/spec/sentry/rails/capture_context_spec.rb

@@ -56,16 +56,21 @@ def call(env)
     end
 
     it "is a no-op when Sentry is not initialized" do
-      allow(Sentry).to receive(:initialized?).and_return(false)
-
       called = false
       app = lambda do |env|
         called = true
         [200, {}, ["ok"]]
       end
 
       env = Rack::MockRequest.env_for("/test")
-      described_class.new(app).call(env)
+
+      # the stub has to be gone before the suite's after hooks run: they skip
+      # clearing events and detaching the log subscribers unless Sentry reports
+      # itself initialized, which would leak log events into later examples
+      RSpec::Mocks.with_temporary_scope do
+        allow(Sentry).to receive(:initialized?).and_return(false)
+        described_class.new(app).call(env)
+      end
 
       expect(called).to eq(true)
       expect(env[Sentry::PropagationContext::ESTABLISHED_ENV_KEY]).to be_nil