fix(core): Make runner disconnected error more user-friendly (no-changelog)

[tomi]

Summary

Before

After

Related Linear tickets, Github issues, and Community forum posts

https://linear.app/n8n/issue/CAT-327/improve-the-default-task-runner-disconnected-error

Review / Merge checklist

• [ ] PR title and summary are descriptive. (conventions)
• [ ] Docs updated or follow-up ticket created.
• [ ] Tests included.
• [ ] PR Labeled with release/backport (if the PR is an urgent fix that needs to be backported)

[codecov[bot]]

Codecov Report

All modified and coverable lines are covered by tests :white_check_mark:

:loudspeaker: Thoughts on this report? Let us know!

[github-actions[bot]]

:warning: Some Cypress E2E specs are failing, please fix them before merging

[cypress[bot]]

n8n    Run #8038

Run Properties:   Passed #8038  •  ececdb09e4: 🌳 master 🖥️ browsers:node18.12.0-chrome107 🤖 PR User 🗃️ e2e/*

Project	n8n
Branch Review	master
Run status	Passed #8038
Run duration	04m 35s
Commit	ececdb09e4: 🌳 master 🖥️ browsers:node18.12.0-chrome107 🤖 PR User 🗃️ e2e/*
Committer	Tomi Turtiainen
View all properties for this run ↗︎

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Test results
Failures	0
Flaky	1
Pending	0
Skipped	0
Passing	478
View all changes introduced in this branch ↗︎

[github-actions[bot]]

:white_check_mark: All Cypress E2E specs passed