fix: increase K8s API rate limits and leader election timeouts

[yuvarajl]

The operator restarts ~every 21h due to leader election lease loss. Root cause: default client-go rate limits (QPS=5, Burst=10) are too low for an operator managing 26+ pods (5 FE + 9+3+3+1 BE + 5 MS). During heavy reconciliation, API calls queue up in the rate limiter and the lease renewal call times out (context deadline exceeded).

Changes:

• Increase K8s API client QPS from 5 to 50, Burst from 10 to 100
• Increase LeaseDuration from 15s to 30s
• Increase RenewDeadline from 10s to 20s
• Increase RetryPeriod from 2s to 5s

Error from logs:
client rate limiter Wait returned an error: context deadline exceeded failed to renew lease doris/e1370669.selectdb.com: context deadline exceeded problem running manager: leader election lost

What problem does this PR solve?

Issue Number: close #xxx

Related PR: #xxx

Problem Summary:

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