Create Plugin: Improve handling of e2e in update cmd

[sunker]

What this PR does / why we need it:

While @Ukochka was updating the plugins in the example repo (see this PR for example), we noticed the create-plugin update cmd is not behaving quite the way we want. In case the plugin did not have any e2e tests at all (Playwright nor Cypress), grafana/e2e scripts and deps were added to the package.json file.

This PR ensures that cypress specific stuff should only be added to package.json in case:

• playwright should be used
• Grafana version is lower than 11 (grafana/e2e was deprecated in 11)
• a cypress folder exist in the plugin root dir

Which issue(s) this PR fixes:
Fixes #919

Special notes for your reviewer:

📦 Published PR as canary version: Canary Versions

✨ Test out this PR locally via:

npm install @grafana/create-plugin@4.10.5-canary.920.29fa67c.0
# or 
yarn add @grafana/create-plugin@4.10.5-canary.920.29fa67c.0

[github-actions]

Hello! 👋 This repository uses Auto for releasing packages using PR labels.

✨ This PR can be merged and will trigger a new patch release.
NOTE: When merging a PR with the release label please avoid merging another PR. For further information see here.

[jackw]

Tested against a couple of plugins and appears to work as expected. Awesome work @sunker ! 🚀

[grafana-plugins-platform-bot]

🚀 PR was released in @grafana/create-plugin@4.10.5 🚀