chore: bump toolbox version to 1.18.12

[s2-infraautomation]

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🤖 Automated Pull Request

This PR was automatically created by Freya as part of the release closure automation workflow.

• Details: Updates toolbox version to 1.18.12 in dev image config
• Triggered by: Release pipeline for 1.18.12-91d8529688
• Generated at: 2026-05-15 16:56:10 UTC
• Review required: Yes, please verify changes before merging

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Note

Low Risk
Low risk version bump limited to release metadata/config; main risk is downstream behavior changes from the updated Toolbox binary.

Overview
Bumps the configured SingleStoreDB Toolbox version from 1.18.11 to 1.18.12 in config.json.

Updates CHANGELOG.md with a new 0.2.81 entry documenting the Toolbox version bump.

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[volodymyr-memsql]

The version is incorrect

[cursor]

Cursor Bugbot has reviewed your changes using default mode and found 1 potential issue.

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