Release v0.23.3

Improvement/enhanced jdk 21 compatibility (#89)

* Replacing URL with URI

* Clean up deleted files and add untracked content

* Upgrade Java version from 11 to 21

- Updated maven.compiler.source and maven.compiler.target in root pom.xml
- Updated compiler configuration in simple-cache module
- Prepared project for JDK 21 compatibility
- Requires JDK 21 runtime for compilation

* Modernize CI and bump to 0.23.0-SNAPSHOT

- Replace outdated CI workflows with modern GitHub Actions
- Update to JDK 21/22 matrix builds with latest actions
- Add automated release workflow on PR merge
- Bump version to 0.23.0-SNAPSHOT across all modules

* Fix Maven plugin versions and JDK compatibility

- Update maven-compiler-plugin to 3.13.0 for JDK 19+ support
- Update maven-surefire-plugin to 3.3.1
- Set JDK target to 19 for compatibility with current environment
- Add JDK 19 to CI matrix testing
- Remove redundant compiler config from simple-cache module

* Enhance JDK-21 compatibility implementation

- Fix Java version configuration: Update from Java 19 to proper JDK-21 (source/target 21)
- Update dependency versions for JDK-21 compatibility:
  - XStream: 1.4.19 → 1.4.20
  - Gson: 2.8.9 → 2.10.1
  - SLF4J: 1.7.35 → 2.0.7
  - JUnit Jupiter: 5.8.2 → 5.10.0
- Fix test robustness: Replace hardcoded paths with dynamic computation
- Add Store.getCacheMetadataStorageAndLookup() getter for better testability
- All tests now pass with JDK-21

* Fix Java version compatibility - set to Java 19