With the announcement that Jenkins will raise its minimum supported Java version from 17 to 21, I conducted compatibility testing. I encountered errors with ‎'readFileFromWorkspace'. The root cause is that, starting with Java 18, the default charset became OS-independent (UTF-8),  which led to issues on Windows environments.

I believe that 'readFileFromWorkspace' should allow specifying Charset as an optional argument, enabling consistent behavior on both Java 17 and Java 21. I am also preparing a pull request on GitHub and would appreciate a review.