chore(deps): bump spring-boot-starter-parent in /boot-data-mongo-gridfs

Bumps [spring-boot-starter-parent](https://github.com/spring-projects/spring-boot) from 2.2.5.RELEASE to 2.5.6.
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v2.2.5.RELEASE...v2.5.6)

---
updated-dependencies:
- dependency-name: org.springframework.boot:spring-boot-starter-parent
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

Signed-off-by: dependabot[bot] <[email protected]>

Author: dependabot[bot]

boot-data-mongo-gridfs/pom.xml

@@ -5,7 +5,7 @@
 	<parent>
 		<groupId>org.springframework.boot</groupId>
 		<artifactId>spring-boot-starter-parent</artifactId>
-		<version>2.2.5.RELEASE</version>
+		<version>2.5.6</version>
 		<relativePath/> <!-- lookup parent from repository -->
 	</parent>
 	<groupId>com.example</groupId>