Bump gson from 2.9.0 to 2.9.1

Bumps [gson](https://github.com/google/gson) from 2.9.0 to 2.9.1.
- [Release notes](https://github.com/google/gson/releases)
- [Changelog](https://github.com/google/gson/blob/master/CHANGELOG.md)
- [Commits](https://github.com/google/gson/compare/gson-parent-2.9.0...gson-parent-2.9.1)

---
updated-dependencies:
- dependency-name: com.google.code.gson:gson
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

extractor/build.gradle

@@ -39,5 +39,5 @@ dependencies {
     testImplementation 'org.junit.jupiter:junit-jupiter-params'
 
     testImplementation "com.squareup.okhttp3:okhttp:3.12.13"
-    testImplementation 'com.google.code.gson:gson:2.9.0'
+    testImplementation 'com.google.code.gson:gson:2.9.1'
 }