fix(limiter): remove the default limit of connect rate

[lafirest]

Remove the default limit of connect rate which used to be 1000/s.

Summary

🤖 Generated by Copilot at 7b51a49

Simplified the schema for listener buckets in emqx_limiter_schema.erl by using a single bucket_opts field. This improves the readability and configurability of the limiter settings.

PR Checklist

Please convert it to a draft if any of the following conditions are not met. Reviewers may skip over until all the items are checked:

• Added tests for the changes
• Changed lines covered in coverage report
• Change log has been added to changes/{ce,ee}/(feat|perf|fix)-<PR-id>.en.md files
• For internal contributor: there is a jira ticket to track this change
• If there should be document changes, a PR to emqx-docs.git is sent, or a jira ticket is created to follow up
• Schema changes are backward compatible

Checklist for CI (.github/workflows) changes

• If changed package build workflow, pass this action (manual trigger)
• Change log has been added to changes/ dir for user-facing artifacts update

[coveralls]

Pull Request Test Coverage Report for Build 4783111000

• 2 of 2 (100.0%) changed or added relevant lines in 1 file are covered.
• 34 unchanged lines in 10 files lost coverage.
• Overall coverage decreased (-0.05%) to 81.144%

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Files with Coverage Reduction	New Missed Lines	%
apps/emqx_gateway/src/emqx_gateway_schema.erl	1	88.89%
apps/emqx/src/emqx_limiter/src/emqx_limiter_server.erl	1	88.62%
apps/emqx/src/emqx_quic_data_stream.erl	1	75.21%
lib-ee/emqx_ee_connector/src/emqx_ee_connector_dynamo.erl	1	69.41%
apps/emqx_resource/src/emqx_resource_manager.erl	2	88.56%
apps/emqx/src/emqx_alarm.erl	2	88.24%
apps/emqx/src/emqx_channel.erl	2	87.33%
apps/emqx_resource/src/emqx_resource_buffer_worker.erl	3	94.42%
apps/emqx_resource/src/emqx_resource_metrics.erl	5	77.78%
apps/emqx/src/emqx_reason_codes.erl	16	85.29%

Totals
Change from base Build 4777157010:	-0.05%
Covered Lines:	25674
Relevant Lines:	31640

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💛 - Coveralls