fix(yum): remove async parameter

[bmphbWV0]

Async parameter returns this log when running the Ansible role : DEBUG Unknown configuration option: async = 1 in /etc/yum.repos.d/confluent.repo

Description

When running the Ansible playbook to upgrade to the version 7.9.7, I saw that these logs were visible in /var/log/dnf.log :

2026-06-25T16:02:34+0200 DEBUG Unknown configuration option: async = 1 in /etc/yum.repos.d/confluent.repo
2026-06-25T16:02:34+0200 DEBUG Unknown configuration option: async = 1 in /etc/yum.repos.d/confluent.repo
2026-06-25T16:02:34+0200 DEBUG Unknown configuration option: async = 1 in /etc/yum.repos.d/confluent.repo
2026-06-25T16:02:34+0200 DEBUG Unknown configuration option: async = 1 in /etc/yum.repos.d/confluent.repo

Fixes # (issue)

Type of change

• Bug fix (non-breaking change which fixes an issue)
• New feature (non-breaking change which adds functionality)
• Breaking change (fix or feature that would cause existing functionality to not work as expected)
• This change requires a documentation update

How Has This Been Tested?

A test server has been used without the parameter "async = 1".

Logs without async parameter :

2026-06-25T16:10:09+0200 DEBUG repo: downloading from remote: Confluent
2026-06-25T16:10:09+0200 DEBUG Confluent: using metadata from Fri 05 Jun 2026 11:22:23 CEST.
2026-06-25T16:10:09+0200 DEBUG repo: downloading from remote: Confluent.control-center-next-gen
2026-06-25T16:10:09+0200 DEBUG Confluent.control-center-next-gen: using metadata from Fri 19 Jun 2026 09:03:25 CEST.
2026-06-25T16:10:09+0200 DEBUG repo: downloading from remote: Confluent.usm-agent
2026-06-25T16:10:09+0200 DEBUG Confluent.usm-agent: using metadata from Mon 22 Jun 2026 09:20:39 CEST.

Checklist:

• Any variable/code changes have been validated to be backwards compatible (doesn't break upgrade)
• I have added tests that prove my fix is effective or that my feature works
• If required, I have ensured the changes can be discovered by cp-ansible discovery codebase
• My code follows the style guidelines of this project
• I have commented my code, particularly in hard-to-understand areas
• I have made corresponding changes to the documentation
• My changes generate no new warnings
• Any dependent changes have been merged and published in downstream modules