Bump org.openjdk.nashorn:nashorn-core from 15.6 to 15.7

Bumps [org.openjdk.nashorn:nashorn-core](https://github.com/openjdk/nashorn) from 15.6 to 15.7.
- [Changelog](https://github.com/openjdk/nashorn/blob/main/CHANGELOG.md)
- [Commits](openjdk/nashorn@release-15.6...release-15.7)

---
updated-dependencies:
- dependency-name: org.openjdk.nashorn:nashorn-core
  dependency-version: '15.7'
  dependency-type: direct:production
  update-type: version-update:semver-minor
...

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

Author: dependabot[bot]

pom.xml

@@ -391,7 +391,7 @@
         <dependency>
           <groupId>org.openjdk.nashorn</groupId>
           <artifactId>nashorn-core</artifactId>
-          <version>15.6</version>
+          <version>15.7</version>
         </dependency>
         <!-- Graal's JS support is not 100% compatible with Java 8.
         <dependency>