Zj/native builds 081225

[zdenek-jonas]

This pull request updates several GitHub Actions workflows to improve the build and deployment process for Maven projects, especially around building native JARs and handling project versioning. The main changes add a reusable workflow for building native JARs, enhance how project versions are set, and streamline the workflow configuration.

Workflow enhancements

• Added a build-native-jar job in both maven_deploy_snapshot.yml and maven_release.yml workflows. This job calls the reusable maven_jni_25.yml workflow after publishing, enabling native JAR builds with appropriate secrets and versioning. [1] [2]

Reusable workflow improvements

• Updated the project-version input in maven_jni_25.yml to be optional and default to UNCHANGED, allowing more flexible invocation from other workflows.
• Modified the Set project version step in maven_jni_25.yml to only run when a new version is provided, preventing unnecessary version changes.

Minor workflow cleanups

• Removed an unnecessary blank line at the start of .github/workflows/maven_release.yml for consistency.
• Minor formatting and comment cleanups in .github/workflows/maven_build_win.yml to streamline the workflow steps. [1] [2]