Update to gradle 9.3.1 and update plugins

[wmdietl]

No description provided.

[wmdietl]

Without this, CI is failing with

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring project ':jspecify'.
> Failed to notify project evaluation listener.
   > org.gradle.api.plugins.internal.DefaultDecoratedConvention

It seems rather odd that gradle doesn't play well together with an not much older version of gradle used in that other project.

[wmdietl]

No, still fails. Can't reproduce locally yet.

[wmdietl]

I looked at the wrong branch. The issue was that the samples-google-prototype-eisop further down was using Gradle 8.9. jspecify/jspecify#768 fixed this and now this PR works.

I think it works even without #16 because the gradle-9.0.0 branch was made before the recent changes in jspecify/jspecify.

[wmdietl]

Copying comments from .github/workflows/build.yml, b/c the change on that line will need to be undone. The change was to use branch gradle-9.0.0 of jspecify/jspecify.

Without this, CI is failing with

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring project ':jspecify'.
> Failed to notify project evaluation listener.
   > org.gradle.api.plugins.internal.DefaultDecoratedConvention

It seems rather odd that gradle doesn't play well together with an not much older version of gradle used in that other project.

---

No, still fails. Can't reproduce locally yet.

---

I looked at the wrong branch. The issue was that the samples-google-prototype-eisop further down was using Gradle 8.9. jspecify/jspecify#768 fixed this and now this PR works.

I think it works even without #16 because the gradle-9.0.0 branch was made before the recent changes in jspecify/jspecify.

[wmdietl]

When using jspecify/jspecify main, which doesn't use Gradle 9.0.0 yet, I again get this error:

* What went wrong:
A problem occurred configuring project ':jspecify'.
> Failed to notify project evaluation listener.
   > org.gradle.api.plugins.internal.DefaultDecoratedConvention

So I'll wait with merging this PR until I merged jspecify/jspecify#755.