task: #3625367 Update @vardot/varbase-e2e to ^2.0.6

Raised @vardot/varbase-e2e from ^2.0.4 to ^2.0.6 in package.json. This project tracks no lock file, so that one line is the whole diff.

Issue: https://www.drupal.org/project/varbase_starter/issues/3625367

2.0.6 fixes Canvas editor step timeouts under load and smartSettle budget bugs: @vardot/varbase-e2e 2.0.6

Test notes

Ran the 09-drupal-canvas-d bucket (tests/features/09-drupal-canvas/09-06-canvas-default-patterns.feature) against a local Varbase Starter site on Varbase 11. On 2.0.6, 7 of 8 scenarios passed in 492s. The same bucket on 2.0.4 failed 4 of 8 in 3001s, every failure a step timeout. The one remaining failure re-runs green and is flaky in its own right, not a timeout.

AI-Generated: Yes

Checkpoints:

• File an issue
• Addition/Change/Update/Fix
• Testing to ensure no regression
• Automated unit testing coverage
• Automated functional testing coverage
• UX/UI designer responsibilities
• Readability
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• Performance
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• Developer Documentation
• User Guide Documentation
• Reviewed by human
• Code review by maintainers
• Full testing and approval
• Credit contributors
• Review with the product owner
• Release notes snippet
• Release