[epilogue]/[wpimath] Fix epilogue's generation of logging code when logging wpi matrices

[henrymilbert]

Describe the bug
When generating logger files that log matrices, epilogue attempts to pass in edu.wpi.first.math.Matrix.struct to the log method. However, struct is not actually a member variable for the Matrix class, despite Matrix implementing StructSerializable. Instead, Matrix has a getStruct(Nat<R> rows, Nat<C> cols) method that requires passing in the number of rows and columns. This means that trying to log matrices using the automatically generated epilogue code causes compilation to fail.

Desktop:

• OS: Windows 11
• Project Information: WPILib version 2025.3.2, Gradle version 7.2, Java version 17