Add skip check on sysprobe set_fact tasks

[KSerrania]

What does this PR do?

Adds when: not datadog_skip_running_check to the system-probe set_fact tasks.

Motivation

The datadog_sysprobe_installed and datadog_sysprobe_enabled facts are only used on tasks with the when: not datadog_skip_running_check condition.
Fixes the CI (as it needs to skip the running check).

[albertvaka]

How did this code get in, if it didn't pass the CI, though?

[KSerrania]

Seems like CircleCI does not run on external contributors' branches from forks (I can't find the jobs that would be associated with #255 neither here: https://circleci.com/gh/DataDog/ansible-datadog nor here: https://circleci.com/gh/dv9io0o/ansible-datadog)

[kevinconaway]

Won't this break the tasks below that rely on those two facts to exist? This would preclude the facts from being defined which will break the checks the below.

[KSerrania]

Won't this break the tasks below that rely on those two facts to exist? This would preclude the facts from being defined which will break the checks the below.

@kevinconaway The two tasks that require these facts also have the when: not datadog_skip_running_check filter, so they won't try to evaluate these facts when datadog_skip_running_check is set to true (thanks to lazy evaluation of the conditions). You can check the CI, which runs with datadog_skip_running_check: true.