Bump okio from 2.1.0 to 2.9.0

Bumps [okio](https://github.com/square/okio) from 2.1.0 to 2.9.0.
- [Release notes](https://github.com/square/okio/releases)
- [Changelog](https://github.com/square/okio/blob/master/CHANGELOG.md)
- [Commits](square/okio@okio-parent-2.1.0...parent-2.9.0)

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

Author: dependabot[bot]

core/build.gradle

@@ -23,7 +23,7 @@ dependencies {
     testImplementation 'com.squareup:kotlinpoet:1.4.0'
     testImplementation 'com.squareup:javapoet:1.11.1'
 
-    implementation "com.squareup.okio:okio:2.1.0"
+    implementation "com.squareup.okio:okio:2.9.0"
     implementation 'io.github.classgraph:classgraph:4.8.86'
 
     // This dependency is only needed as a "sample" compiler plugin to test that