Revert "Optimize TestConfig.reset to only run when context changes"

This reverts the optimization because it broke test isolation.
Tests use Config.config.set() to override config values, and without
TestConfig.reset between tests, these changes persist and pollute
subsequent tests.

For example, tests setting max_annotations_per_resource=1 caused
other tests to fail with "AnnotationLimitExceeded" errors.

Author: johha

spec/spec_helper.rb

@@ -136,11 +136,8 @@
       Sequel::Deprecation.output = StringIO.new
       Sequel::Deprecation.backtrace_filter = 5
 
-      new_context = example.metadata[:job_context] || :api
-      if TestConfig.context != new_context
-        TestConfig.context = new_context
-        TestConfig.reset
-      end
+      TestConfig.context = example.metadata[:job_context] || :api
+      TestConfig.reset
 
       VCAP::CloudController::SecurityContext.clear
       VCAP::Request.current_id = nil