fix: change producer reconnect error logs to warn logs

[RobertIndie]

Motivation

During producer reconnection, retryable errors are currently logged at the error level. These cases are expected and should not be treated as hard failures. They should be logged at the warning level instead.

Modifications

• Change producer reconnect error logs from error to warning level

Preview

time="2025-12-08T16:52:35+08:00" level=warning msg="Failed to reconnect to broker, will retry later." error="expected error" producerID=1 producer_name=standalone-425-5 topic="persistent://public/default/my-topic-878937000"

Does this pull request potentially affect one of the following parts:

If yes was chosen, please highlight the changes

• Dependencies (does it add or upgrade a dependency): (yes / no)
• The public API: (yes / no)
• The schema: (yes / no / don't know)
• The default values of configurations: (yes / no)
• The wire protocol: (yes / no)

Documentation

• Does this pull request introduce a new feature? (yes / no)
• If yes, how is the feature documented? (not applicable / docs / GoDocs / not documented)
• If a feature is not applicable for documentation, explain why?
• If a feature is not documented yet in this PR, please create a followup issue for adding the documentation

[Copilot]

Pull request overview

This PR changes the logging level for producer reconnection failures from error to warning for retryable errors. This is appropriate since these failures are expected during normal reconnection attempts and don't represent hard failures.

• Moved the reconnect failure log from error to warning level
• Repositioned the log statement to occur after specific error type checks
• Updated the log message to be more descriptive ("Failed to reconnect to broker, will retry later.")

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[thomas-bousquet]

Thanks for changing the log level, so far we were changing from ERROR to WARN level with the client wrapper we built around the Go Pulsar client.

I believe these 2 messages could probably be changed as well:

1. Failed to create consumer at reconnect
2. Failed to create producer at reconnect