MLE-24682 network filtering fix

[vitalykorolev]

add 'modprobe br_netfilter' command to ensure that netfiltering works

[Copilot]

Pull Request Overview

This PR adds the modprobe br_netfilter command to the Jenkins pipeline to ensure proper network filtering functionality in VM environments where bridge traffic may be disabled.

• Adds kernel module loading command before existing bridge configuration
• Ensures the br_netfilter module is loaded to support netfiltering operations

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