OpenExeConfiguration works with dll.config

### Type of issue

Outdated article

### Description

OpenExeConfiguration also works with dll paths like 'something.dll' when there is a 'something.dll.config'.
The '*.dll.config' file seems to be the default in .NET Core and '*.exe.config' do not usually get generated there.

### Page URL

https://learn.microsoft.com/en-us/dotnet/api/system.configuration.configurationmanager.openexeconfiguration?view=windowsdesktop-10.0#system-configuration-configurationmanager-openexeconfiguration(system-string)

### Content source URL

https://github.com/dotnet/dotnet-api-docs/blob/main/xml/System.Configuration/ConfigurationManager.xml

### Document Version Independent Id

f335652d-9391-eb66-5a28-0e0374022bf2

### Platform Id

f1ddd0c0-8a36-65bf-8e8b-1db97841d9a9

### Article author

@dotnet-bot