Bump net.jsign:jsign-maven-plugin from 2.1 to 6.0 in /owlcms-windows

Bumps [net.jsign:jsign-maven-plugin](https://github.com/ebourg/jsign) from 2.1 to 6.0.
- [Release notes](https://github.com/ebourg/jsign/releases)
- [Changelog](https://github.com/ebourg/jsign/blob/master/RELEASE.md)
- [Commits](ebourg/jsign@2.1...6.0)

---
updated-dependencies:
- dependency-name: net.jsign:jsign-maven-plugin
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

owlcms-windows/pom.xml

@@ -288,7 +288,7 @@
                     <plugin>
                         <groupId>net.jsign</groupId>
                         <artifactId>jsign-maven-plugin</artifactId>
-                        <version>2.1</version>
+                        <version>6.0</version>
                         <executions>
                             <execution>
                                 <goals>