RATIS-2441. Set encoding for maven-resources-plugin

[adoroszlai]

What changes were proposed in this pull request?

Fix warning about properties encoding:

[INFO] --- resources:3.3.1:resources (default-resources) @ ratis-docs ---
...
[INFO] The encoding used to copy filtered properties files have not been set. This means that the same encoding will be used to copy filtered properties files as when copying other filtered resources. This might not be what you want! Run your build with --debug to see which files might be affected. Read more at https://maven.apache.org/plugins/maven-resources-plugin/examples/filtering-properties-files.html

by setting propertiesEncoding for maven-resources-plugin according to doc.

ratis-version.properties is read using Properties class, so encoding should be ISO-8859-1.

ratis/ratis-common/src/main/java/org/apache/ratis/util/VersionInfo.java

Lines 100 to 102 in 5217431

	try (InputStream in = clazz.getClassLoader().getResourceAsStream(RATIS_VERSION_PROPERTIES)) {
	if (in != null) {
	properties.load(in);

https://issues.apache.org/jira/browse/RATIS-2441

How was this patch tested?

Warning is gone:
https://github.com/adoroszlai/ratis/actions/runs/26450457188/job/77883526958

[szetszwo]

+1 the change looks good.