Bump net.sf.jt400:jt400 from 11.1 to 20.0.6

Bumps [net.sf.jt400:jt400](https://github.com/IBM/JTOpen) from 11.1 to 20.0.6.
- [Release notes](https://github.com/IBM/JTOpen/releases)
- [Changelog](https://github.com/IBM/JTOpen/blob/main/changes.html)
- [Commits](IBM/JTOpen@v11.1...v20.0.6)

---
updated-dependencies:
- dependency-name: net.sf.jt400:jt400
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

pom.xml

@@ -53,7 +53,7 @@
         <!-- We call it db2i here but it's actually jt400
          For more information: https://www.ibm.com/support/pages/jtopen-jdbc-driver-%E2%80%93-alternate-server-support
          -->
-        <db2i.version>11.1</db2i.version>
+        <db2i.version>20.0.6</db2i.version>
     </properties>
 
     <repositories>