[nrf fromlist] Revert "tests: arm_thread_swap: Add overlay for nRF54H20"

This reverts commit 28bd478.

This commit can be reverted as the cause of test failure
has been removed in ipc service by increasing workqueue stack size.

Upstream PR #: 86103

Signed-off-by: Adam Kondraciuk <[email protected]>

Author: adamkondraciuk