Can't suppress WHITESPACE warnings

I've tried adding an empty .editorconfig file in order to slowly add rules to an existing project.
When testing it with `--severity error --verify-no-changes` I get WHITESPACE errors for lines with trailing whitespace.
When I try setting `trim_trailing_whitespace` to `false` or `unset` I still get those errors.
I've tried disabling all sorts of dotnet_diagnostic codes like:
```
dotnet_diagnostic.IDE0055.severity = none
dotnet_diagnostic.SA1028.severity = none
dotnet_diagnostic.CA1062.severity = none
dotnet_diagnostic.CA1801.severity = none
dotnet_diagnostic.CA1822.severity = none
dotnet_diagnostic.SA1000.severity = none
dotnet_diagnostic.SA1001.severity = none
dotnet_diagnostic.SA1005.severity = none
dotnet_diagnostic.SA1025.severity = none
```
But nothing seems to work.
How can I disable this rule?