Summary:
Instead of printing pg_upgrade check logs using the tee command, YBA will write the logs on the tmp log file and then parse it in YBA.
The tee command cannot be used when node-agent is enabled.

Original commit: 7b3d09fef1ea4e01681dcbc48596035ff3faa163 / D43499

Test Plan: Tested manually by performing a failed and successful software upgrade precheck on a node-agent enabled universe.

Reviewers: yshchetinin, nsingh, daniel

Reviewed By: nsingh

Subscribers: yugaware

Differential Revision: https://phorge.dev.yugabyte.com/D43574