Bump PerlOnJava to 5.44.0

[fglock]

Summary

• bump PerlOnJava and Perl compatibility metadata to 5.44.0
• update launchers, build files, Config.pm, examples, and documentation
• make Configure.pl version updates safer and keep generated configuration in sync
• fix the Maven clean test lifecycle and launcher classpath fallback
• refresh public documentation and remove conflicting build, packaging, feature, and support claims
• update the Larry Wall copyright year to 2026

Validation

• mvn clean verify (575 tests, 0 failures, 2 skipped)
• ./gradlew clean build
• make check-links (523 links checked, 0 errors)
• possessive quantifier regression test (12/12 passed)
• git diff --check

Dependency

This is stacked on #867. After #867 merges, retarget this PR from release/pre-5.44 to master.