Auto merge hamcrest (#7)

`hamcrest` is a unit testing dependency, so we can assume it’s safe to
upgrade if the tests pass.

.github/workflows/default-dependabot-automerge-whitelist.conf

@@ -8,3 +8,4 @@ org.assertj:assertj-core minor
 com.adobe.testing:s3mock-testcontainers minor
 org.testcontainers:testcontainers-bom minor
 org.wiremock:wiremock-standalone minor
+org.hamcrest:hamcrest-core minor