Update hard-coded stubs in tests to use Ruby 3.4 backtrace syntax

[kaylareopelle]

Some of our tests have hard-coded stubs with backtraces with the pre-Ruby 3.4 format. We should update the stubs to point to the example conditionally based on the Ruby version. See "Compatibility Issues" heading on this post for details.

The work for Thread Profile and Backtrace Node tests will be resolved as part of another issue.

The regex used to find these tests is: `

• newrelic-ruby-agent/test/new_relic/agent/threading/agent_thread_test.rb

  Lines 140 to 142 in 49cbf98

  	"/Users/jclark/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/newrelic_rpm-3.5.3.452.dev/lib/new_relic/agent/agent.rb:200:in `start_worker_thread'",
  	"/Users/jclark/.rbenv/versions/1.9.3-p194/lib/ruby/gems/1.9.1/gems/thin-1.5.0/lib/thin/backends/base.rb:300:in `block (3 levels) in run'"
  	]

• newrelic-ruby-agent/test/new_relic/agent/stats_engine/stats_hash_test.rb

  Line 197 in 9be0b17

  exception = NoMethodError.new("borked default proc gives a NoMethodError on `yield'")

• newrelic-ruby-agent/test/new_relic/http_client_test_cases.rb

  Line 438 in 285de8a

  .raises(NoMethodError, "undefined method `pop_scope'")

• newrelic-ruby-agent/test/multiverse/suites/aws_sdk_lambda/aws_sdk_lambda_instrumentation_test.rb

  Line 87 in f15914e

  backtrace = ["/var/task/lambda_function.rb:4:in `lambda_handler'",

[workato-integration]

https://new-relic.atlassian.net/browse/NR-348651