fix: resolve JDK 11+ compiler and deprecation warnings

[chaitanyakatore]

Resolved Deprecated URL Constructor

• Location: src/main/java/zowe/client/sdk/rest/ZosmfRequest.java
• Details: In Java 20+, the new URL(String) constructor is deprecated due to potential parsing issues and lack of URL validation.
• Fix: Replaced new URL(url).toURI() with the recommended new URI(url).toURL(). This approach is fully compatible with Java 11 through Java 22+ and compiles warning-free.

Resolved Compiler System Modules Warning

• Location: pom.xml
• Details: Compiling with 11 and 11 on newer JDK versions raises a warning regarding -system module location settings.
• Fix: Configured the maven-compiler-plugin to use 11. This properly informs the compiler to verify compatibility against JDK 11 APIs and resolves the system modules warning.

[frankgiordano]

Thank you for the contribution. I’ve reviewed the changes and will merge them and publish a new point release.