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

:sparkles: Test out this PR locally via: ```bash 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 ```

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[grafana-plugins-platform-bot[bot]]

:rocket: PR was released in @grafana/create-plugin@4.10.5 :rocket: