Bump h2 from 1.3.170 to 2.2.220 in /showcase/bookstore

Bumps [h2](https://github.com/h2database/h2database) from 1.3.170 to 2.2.220.
- [Release notes](https://github.com/h2database/h2database/releases)
- [Commits](https://github.com/h2database/h2database/commits/version-2.2.220)

---
updated-dependencies:
- dependency-name: com.h2database:h2
  dependency-type: direct:production
...

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

showcase/bookstore/pom.xml

@@ -45,7 +45,7 @@
       <dependency>
          <groupId>com.h2database</groupId>
          <artifactId>h2</artifactId>
-         <version>1.3.170</version>
+         <version>2.2.220</version>
       </dependency>
 
       <dependency>