Add conformance marker to test_rhel_os.py (#2946)

##### Short description:
Add conformance marker to test_rhel_os.py

##### More details:
Adding RHEL basic tests using data sources to the conformance tests used
by `https://github.com/openshift-cnv/ocp-virt-validation-checkup/`

##### What this PR does / why we need it:
Add extra coverage for
https://github.com/openshift-cnv/ocp-virt-validation-checkup/

##### jira-ticket:
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pull request to the jira and close it when the pull request is merged
If the task is not tracked by a Jira ticket, just write "NONE".
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https://issues.redhat.com/browse/CNV-68864


<!-- This is an auto-generated comment: release notes by coderabbit.ai
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## Summary by CodeRabbit

* **Tests**
* Added conformance annotations to VM creation and deletion test classes
for improved test organization and tracking.

<sub>✏️ Tip: You can customize this high-level summary in your review
settings.</sub>

<!-- end of auto-generated comment: release notes by coderabbit.ai -->

Signed-off-by: rkishner <[email protected]>

Author: RoniKishner

tests/infrastructure/instance_types/supported_os/test_rhel_os.py

@@ -30,6 +30,7 @@
 TESTS_MODULE_IDENTIFIER = "TestCommonInstancetypeRhel"
 
 
+@pytest.mark.conformance
 @pytest.mark.arm64
 @pytest.mark.s390x
 @pytest.mark.smoke
@@ -153,6 +154,7 @@ def test_verify_virtctl_guest_agent_data_after_migrate(self, golden_image_rhel_v
         )
 
 
+@pytest.mark.conformance
 @pytest.mark.arm64
 @pytest.mark.smoke
 @pytest.mark.gating