Bump io.spring.nullability in the development-dependencies group

Bumps the development-dependencies group with 1 update: [io.spring.nullability](https://github.com/spring-gradle-plugins/nullability-plugin).


Updates `io.spring.nullability` from 0.0.8 to 0.0.9
- [Release notes](https://github.com/spring-gradle-plugins/nullability-plugin/releases)
- [Commits](spring-gradle-plugins/nullability-plugin@v0.0.8...v0.0.9)

---
updated-dependencies:
- dependency-name: io.spring.nullability
  dependency-version: 0.0.9
  dependency-type: direct:production
  update-type: version-update:semver-patch
  dependency-group: development-dependencies
...

Signed-off-by: dependabot[bot] <support@github.com>

Author: dependabot[bot]

build.gradle

@@ -22,7 +22,7 @@ plugins {
     id 'io.spring.antora.generate-antora-yml' version '0.0.1'
     id 'com.google.protobuf' version '0.9.6' apply false
     id 'io.freefair.aggregate-javadoc' version '9.1.0'
-    id 'io.spring.nullability' version '0.0.8' apply false
+    id 'io.spring.nullability' version '0.0.9' apply false
 }
 
 if (isCI) {