chore(demo): Replace auto-sending metrics with a tool button

[limbonaut]

Sending metrics by default creates some noise in the output, which may distract from other things happening in the demo project. This PR makes sending metrics a tool action, which toggles sending. To start sending metrics, you now need to press the corresponding tool button, and you can stop sending metrics by pressing it again.

[github-actions]

Semver Impact of This PR

🟢 Patch (bug fixes)

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Internal Changes 🔧

Deps

• Update Native SDK to v0.13.4 by github-actions in #621
• Update Sentry Android to v8.37.1 by github-actions in #616
• Update Sentry JavaScript to v10.46.0 by github-actions in #615
• Update Sentry Android to v8.37.0 by github-actions in #614
• Update gdUnit 4 to v6.1.2 by github-actions in #610
• Bump json from 2.18.0 to 2.19.2 by dependabot in #604
• Update Cocoa SDK to v9.8.0 by github-actions in #605
• Update Sentry JavaScript to v10.45.0 by github-actions in #607
• Update Native SDK to v0.13.3 by github-actions in #606

Other

• (demo) Replace auto-sending metrics with a tool button by limbonaut in #623

• (deps-dev) Bump picomatch from 2.3.1 to 2.3.2 in /src/sentry/javascript/bridge by dependabot in #617
• (web) Adapt and run E2E tests on Web platform by limbonaut in #611
• Add PR validation workflow by stephanie-anderson in #618
• Pin GitHub Actions to full-length commit SHAs by joshuarli in #612
• Add E2E tests for structured logs and metrics by limbonaut in #602
• Stabilize flaky SauceLabs integration tests by limbonaut in #601

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[limbonaut]

Reading console output is challenging while having demo metrics enabled all the time.