Don't apply Spring Boot plugin in sentry-spring-boot-jakarta

[lcian]

📜 Description

Restores apply false on the Spring Boot plugin in this module, which was already present before
https://github.com/getsentry/sentry-java/blob/10dfe0c7f208f7c5675f5bf2517d121f938b34b0/sentry-spring-boot-jakarta/build.gradle.kts
It must've been left out by mistake in the version catalog migration

If the plugin is applied then the build will try to run the bootJar task to create an application Jar which will fail.

I'm not sure why CI and/or craft/release action didn't detect this.

💡 Motivation and Context

Fixes #4455

💚 How did you test it?

The jar is present locally

📝 Checklist

• 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