java.lang.IllegalStateException: No builtin diff provider

### Apache NetBeans version

Apache NetBeans 20

### What happened

```
java.lang.IllegalStateException: No builtin diff provider
at org.netbeans.modules.diff.DiffModuleConfig.getBuiltinProvider(DiffModuleConfig.java:253)
at org.netbeans.modules.diff.DiffModuleConfig.setOptions(DiffModuleConfig.java:235)
at org.netbeans.modules.diff.options.DiffOptionsController.applyChanges(DiffOptionsController.java:62)
at org.netbeans.modules.options.advanced.Model$DelegatingController.applyChanges(Model.java:295)
at org.netbeans.modules.options.advanced.Model.applyChanges(Model.java:178)
at org.netbeans.modules.options.advanced.AdvancedPanel.applyChanges(AdvancedPanel.java:83)
at org.netbeans.modules.options.advanced.AdvancedPanelController.applyChanges(AdvancedPanelController.java:53)
at org.netbeans.modules.options.CategoryModel$Category.applyChanges(CategoryModel.java:379)
at org.netbeans.modules.options.CategoryModel$Category.access$1100(CategoryModel.java:302)
at org.netbeans.modules.options.CategoryModel.save(CategoryModel.java:198)
at org.netbeans.modules.options.OptionsPanel.save(OptionsPanel.java:288)
at org.netbeans.modules.options.OptionsDisplayerImpl$OptionsPanelListener$3.run(OptionsDisplayerImpl.java:515)
at org.netbeans.modules.progress.ui.RunOffEDTImpl$3.run(RunOffEDTImpl.java:252)
at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1420)
at org.netbeans.modules.openide.util.GlobalLookup.execute(GlobalLookup.java:45)
at org.openide.util.lookup.Lookups.executeWith(Lookups.java:287)
[catch] at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2035)
```

### Language / Project Type / NetBeans Component

IDE itself

### How to reproduce

nothing to reproduce. The IDE just threw the exception.
```
java.lang.IllegalStateException: No builtin diff provider
at org.netbeans.modules.diff.DiffModuleConfig.getBuiltinProvider(DiffModuleConfig.java:253)
at org.netbeans.modules.diff.DiffModuleConfig.setOptions(DiffModuleConfig.java:235)
at org.netbeans.modules.diff.options.DiffOptionsController.applyChanges(DiffOptionsController.java:62)
at org.netbeans.modules.options.advanced.Model$DelegatingController.applyChanges(Model.java:295)
at org.netbeans.modules.options.advanced.Model.applyChanges(Model.java:178)
at org.netbeans.modules.options.advanced.AdvancedPanel.applyChanges(AdvancedPanel.java:83)
at org.netbeans.modules.options.advanced.AdvancedPanelController.applyChanges(AdvancedPanelController.java:53)
at org.netbeans.modules.options.CategoryModel$Category.applyChanges(CategoryModel.java:379)
at org.netbeans.modules.options.CategoryModel$Category.access$1100(CategoryModel.java:302)
at org.netbeans.modules.options.CategoryModel.save(CategoryModel.java:198)
at org.netbeans.modules.options.OptionsPanel.save(OptionsPanel.java:288)
at org.netbeans.modules.options.OptionsDisplayerImpl$OptionsPanelListener$3.run(OptionsDisplayerImpl.java:515)
at org.netbeans.modules.progress.ui.RunOffEDTImpl$3.run(RunOffEDTImpl.java:252)
at org.openide.util.RequestProcessor$Task.run(RequestProcessor.java:1420)
at org.netbeans.modules.openide.util.GlobalLookup.execute(GlobalLookup.java:45)
at org.openide.util.lookup.Lookups.executeWith(Lookups.java:287)
[catch] at org.openide.util.RequestProcessor$Processor.run(RequestProcessor.java:2035)
```

### Did this work correctly in an earlier version?

No / Don't know

### Operating System

Windows 7 Ultimate

### JDK

jdk-21.0.2

### Apache NetBeans packaging

Apache NetBeans binary zip

### Anything else

_No response_

### Are you willing to submit a pull request?

Yes

Start with org.netbeans.modules.diff.DiffModuleConfig, especially getBuiltinProvider and setOptions, then follow DiffOptionsController.applyChanges. Reproduce by applying the Diff options in Apache NetBeans 20 on the reported setup and determine why no builtin diff provider is available. Done means applying the options no longer throws IllegalStateException.

Written by the indexing model from the issue text.