Build fails in gradle 9.0.0

```
Welcome to Gradle 9.0.0!

Here are the highlights of this release:
- Configuration Cache is the recommended execution mode
- Gradle requires JVM 17 or higher to run
- Build scripts use Kotlin 2.2 and Groovy 4.0
- Improved Kotlin DSL script compilation avoidance

For more details see https://docs.gradle.org/9.0.0/release-notes.html

Starting a Gradle Daemon (subsequent builds will be faster)

[Incubating] Problems report is available at: file:///tmp/google-tsunami-security-scanner-git/src/tsunami-security-scanner/build/reports/problems/problems-report.html

FAILURE: Build failed with an exception.

* Where:
Build file '/tmp/google-tsunami-security-scanner-git/src/tsunami-security-scanner/build.gradle' line: 51

* What went wrong:
A problem occurred evaluating root project 'tsunami'.
> Could not set unknown property 'sourceCompatibility' for project ':tsunami-common' of type org.gradle.api.Project.

* Try:
> Run with --stacktrace option to get the stack trace.
> Run with --info or --debug option to get more log output.
> Run with --scan to generate a Build Scan (Powered by Develocity).
> Get more help at https://help.gradle.org.

Deprecated Gradle features were used in this build, making it incompatible with Gradle 10.

You can use '--warning-mode all' to show the individual deprecation warnings and determine if they come from your own scripts or plugins.

For more on this, please refer to https://docs.gradle.org/9.0.0/userguide/command_line_interface.html#sec:command_line_warnings in the Gradle documentation.

BUILD FAILED in 35s
```