fix: fix heisenbug and simplify tests

[eduardacoppo]

This PR fixes this heisenbug:

1) Failure:
 OroGen.linux_gpios.Task::using 'init' connection#test_0001_does not keep last written value when a new connection is established without 'init: true' [/buildbot/wetpaint-build/build/drivers/orogen/linux_gpios/test/task_test.rb:216]:
 1 unmet expectations
 OroGen.linux_gpios.Task<id:162>(conf: ["default"], name: state, orocos_name: state_task_under_test, read_only: false).r_states should not have received a new sample, but it received one: {
   time=2025-02-17 18:13:31.464762 +0000,
   states=[{
      time=2025-02-17 18:13:31.464762 +0000,
      data=0
  }]
}

and simplifies the tests.