Bump org.jetbrains.kotlin:kotlin-scripting-compiler-embeddable

Bumps [org.jetbrains.kotlin:kotlin-scripting-compiler-embeddable](https://github.com/JetBrains/kotlin) from 2.1.20 to 2.1.21.
- [Release notes](https://github.com/JetBrains/kotlin/releases)
- [Changelog](https://github.com/JetBrains/kotlin/blob/master/ChangeLog.md)
- [Commits](JetBrains/kotlin@v2.1.20...v2.1.21)

---
updated-dependencies:
- dependency-name: org.jetbrains.kotlin:kotlin-scripting-compiler-embeddable
  dependency-version: 2.1.21
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

Author: dependabot[bot]

extensions/schema-registry/confluent/pom.xml

@@ -25,7 +25,7 @@
             <dependency>
                 <groupId>org.jetbrains.kotlin</groupId>
                 <artifactId>kotlin-scripting-compiler-embeddable</artifactId>
-                <version>2.1.20</version>
+                <version>2.1.21</version>
             </dependency>
             <dependency>
                 <groupId>org.json</groupId>

integration-tests/kafka-json-schema-apicurio2/pom.xml

@@ -23,7 +23,7 @@
             <dependency>
                 <groupId>org.jetbrains.kotlin</groupId>
                 <artifactId>kotlin-scripting-compiler-embeddable</artifactId>
-                <version>2.1.20</version>
+                <version>2.1.21</version>
             </dependency>
             <dependency>
                 <groupId>org.json</groupId>