Bump mybatis from 3.4.5 to 3.5.6 in /learn-mybatis3

Bumps [mybatis](https://github.com/mybatis/mybatis-3) from 3.4.5 to 3.5.6.
- [Release notes](https://github.com/mybatis/mybatis-3/releases)
- [Commits](mybatis/mybatis-3@mybatis-3.4.5...mybatis-3.5.6)

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

learn-mybatis3/pom.xml

@@ -17,7 +17,7 @@
  <dependency>
  <groupId>org.mybatis</groupId>
  <artifactId>mybatis</artifactId>
- <version>3.4.5</version>
+ <version>3.5.6</version>
  </dependency>
  <dependency>
  <groupId>com.oracle</groupId>