[Bug] PlantUml local rendering on Ubuntu: java.exe not found

**PlantUML local rendering on Ubuntu: java.exe not found**
When trying to build PlantUML files locally during a docfx build using the plantuml.jar on a linux machine, an error gets thrown:

It seems to want to access the java.exe to run the jar.
I tried to run the exact same project on a Windows 10 Machine, where it ran as expected.

**To Reproduce**
Steps to reproduce the behavior:
1. Install DocFx on an Ubuntu Machine and initialize a project
3. Add a plantUml Diagram to your docfx project
4. Install the plantuml.jar and add to project: https://plantuml.com/de/download (I used MIT)
5. Edit docfx.json:
5. Run docfx build

**Expected behavior**
docfx build should run and build the PlantUML Diagrams using the locally installed plantuml.jar.

**Context:**
- OS: Ubuntu 24.04.1 LTS
- Docfx version: 2.78.2
- Java version: openjdk 21.0.5 2024-10-15

**Additional context**
Using the remote server plantuml.com is not possible, due to the machine being offline.