docs(readme): Link Maven Central shields to artifact pages

[runningcode]

📜 Description

Wraps every Maven Central version shield in the README package table with a link to the corresponding artifact page on Maven Central (https://central.sonatype.com/artifact/io.sentry/<artifact>).

💡 Motivation and Context

The shields previously were not clickable, so there was no direct way to jump from a package row to its Maven Central listing. Making the shields into links lets readers quickly navigate to the artifact page to browse versions, POMs, and dependency snippets.

💚 How did you test it?

Rendered the README locally and spot-checked that a few of the shields link to the correct artifact on central.sonatype.com.

📝 Checklist

• I added GH Issue ID & Linear ID
• I added tests to verify the changes.
• No new PII added or SDK only sends newly added PII if sendDefaultPII is enabled.
• I updated the docs if needed.
• I updated the wizard if needed.
• Review from the native team if needed.
• No breaking change or entry added to the changelog.
• No breaking change for hybrid SDKs or communicated to hybrid SDKs.

🔮 Next steps

#skip-changelog

[github-actions]

Semver Impact of This PR

🟢 Patch (bug fixes)

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[sentry]

📲 Install Builds

Android

🔗 App Name	App ID	Version	Configuration
SDK Size	io.sentry.tests.size	8.39.1 (1)	release

⚙️ sentry-android Build Distribution Settings

[romtsn]

nice!