ansible: disable runner name randomization

In commit 151eda0 RANDOM_RUNNER_SUFFIX was set to true in order to
mitigate runner registration errors [1].

This had a side effect of stale runners accumulating,, eventually
reaching 10k runners limit in the default runner group on BPF CI.

Now that the registration errors appear to be addressed by GitHub,
disable runner name randomization.

[1] actions/runner#3857 (comment)

Author: theihor

ansible/roles/runner/tasks/main.yml

@@ -105,8 +105,7 @@
       RUNNER_SCOPE=org
       ORG_NAME={{ item.0.name }}
       {% endif %}
-      RUNNER_NAME_PREFIX={{ runner_name_prefix }}-{{ 'worker-%02d' | format(item.1) }}
-      RANDOM_RUNNER_SUFFIX=true
+      RUNNER_NAME={{ runner_name_prefix }}-{{ 'worker-%02d' | format(item.1) }}
       DISABLE_AUTO_UPDATE=true
   loop: "{{ runners | subelements('workers') }}"