Bump johnzon-core from 1.2.20 to 1.2.21

Bumps johnzon-core from 1.2.20 to 1.2.21.

---
updated-dependencies:
- dependency-name: org.apache.johnzon:johnzon-core
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

parent/pom.xml

@@ -150,7 +150,7 @@
       <dependency>
         <groupId>org.apache.johnzon</groupId>
         <artifactId>johnzon-core</artifactId>
-        <version>1.2.20</version>
+        <version>1.2.21</version>
       </dependency>
 
       <dependency>