fix/incorrect persistence leader aquire check

[stanley2058]

set returns false if the current server is already a leader. In this PR, we get the current leader immediately after set to check if the current server is the leader.

[Copilot]

Pull Request Overview

This PR fixes a bug in the persistence leader acquisition check by changing the logic from relying on the Redis SET command's return value to explicitly checking if the current server became the leader after the SET operation.

• Changed from using the return value of redis.set() to explicitly checking the current leader after the operation
• Added a separate redis.get() call to verify if this server is now the leader
• Maintains the same conditional logic flow while fixing the incorrect leader check

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