tests: pytestified test_cc_rsyslog.py

[MoeSalah1999]

Proposed Commit Message

test: Converted test_cc_rsyslog.py from unittest to pytest, made sure test case classes don't inherit from TestCase, used pytest fixtures instead of unittest setUp method, and lastly converted self.assert to plain assert.
Fixes GH-#6427 

Additional Context

Test Steps

Merge type

• [x] Squash merge using "Proposed Commit Message"
• [ ] Rebase and merge unique commits. Requires commit messages per-commit each referencing the pull request number (#<PR_NUM>)

[MoeSalah1999]

@blackboxsw could you please verify this?

[blackboxsw]

Additionally please format the proposed commit message suggestion to correctly represent conventional commits. The line-length is too long for our commit messages.

And the footer of a commit message should not say Fixes GH-6427 unless that full issue was resolved for all cases. Instead use Related GH-6427 please.