GD-32: Create test case should use configured text ident settings

[FeralBytes]

No Duplicates.

The used Godot version:
v4.0.beta4.official [e6751549c] Vulkan AKA Forward+

OS including version:
OS: Linux Mint 20.3 Cinnamon 5.2.7
Kernel: 5.4.0-131-generic
CPU: AMD Ryzen 9 3900X 12-Core Processor × 12
GPU: Advanced Micro Devices, Inc. [AMD/ATI] Navi 10 [Radeon RX 5700 XT]

Describe the bug
Specific Error from Godot:

res://test/SettingsTest.gd:18 - Parse Error: Used tab character for indentation instead of space as used before in the file.

Steps to Reproduce
Steps to reproduce the behavior:

1. Click on Editor
2. Click on Editor Settings
3. Click on Text Editor -> Behavior
4. Set Indent Type to Spaces
5. Set Convert Indent on Save to On.
6. Install GDUnit4
7. Ensure GDUnit4 is enabled in plugins in case of crash.
8. Build a test file in the test directory as GDUnit4 does not yet have this capability.
9. Right click on a function in the GDScript file for the corresponding test file that you created and choose Create Test.
10. Observer the errors below in the output panel.

Minimal reproduction project:
GDUnit4NullReturnIssue.zip

Note:
This is also an issue for GDUnit3 but it does not fail in Godot 3.