dependabot: bump org.gradle.test-retry from 1.5.8 to 1.5.9 (#618)

Bumps org.gradle.test-retry from 1.5.8 to 1.5.9.

---
updated-dependencies:
- dependency-name: org.gradle.test-retry
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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Co-authored-by: dependabot[bot] <49699333+dependabot[bot]@users.noreply.github.com>

spi/build.gradle

@@ -11,7 +11,7 @@ plugins {
     id 'jacoco'
     id 'maven-publish'
     id 'signing'
-    id "org.gradle.test-retry" version "1.5.8"
+    id "org.gradle.test-retry" version "1.5.9"
 }
 
 apply plugin: 'opensearch.java'