Warning C4335: Mac file format detected: please convert the source file to either DOS or UNIX format

### Description

I am configuring the GitHub Actions for the module `ITKIOTransformDCMTK` and this module uses `DCMTK` as a dependency in `ITK`.

### Steps to Reproduce

The GitHub Actions configuration can be found [here](https://github.com/mseng10/ITKIOTransformDCMTK/blob/github-actions/.github/workflows/build-test-package.yml), or you can follow the steps below.

git clone https://github.com/InsightSoftwareConsortium/ITK.git
cd ITK
git checkout v5.1.1

cd ..
mkdir ITK-build
cd ITK-build
call "C:\Program Files (x86)\Microsoft Visual Studio\2019\Enterprise\VC\Auxiliary\Build\vcvars64.bat"
cmake -DCMAKE_C_COMPILER:FILEPATH="cl.exe" -DModule_ITKDCMTK:BOOL=ON - DModule_ITKIODCMTK:BOOL=ON -DBUILD_SHARED_LIBS:BOOL=ON -DCMAKE_CXX_COMPILER="cl.exe" -DCMAKE_BUILD_TYPE:STRING="Release" -DBUILD_TESTING:BOOL=OFF -GNinja ../ITK
ninja

#ITKIOTranformDCMTK configuration
ctest --output-on-failure -j 2 -V -S dashboard.cmake

### Expected behavior

No warnings generated when compiled with `DCMTK`.

### Actual behavior

In `cdash`, I get the following compiler warnings when building `ITK` and `ITKIOTransformDCMTK` [output](https://open.cdash.org/build/6867622).

The source of the warning can be characterized below:

D:\a\ITKIOTransformDCMTK\ITK-build\Modules\ThirdParty\DCMTK\ITKDCMTK_ExtProject-build\config\include\dcmtk/config/arith.h(1):
Warning C4335: Mac file format detected: please convert the source file to either DOS or UNIX format

### Reproducibility

This warning is generated 100% of the time.

### Versions
- ITK: [`v5.1.1`](https://github.com/InsightSoftwareConsortium/ITK/releases/tag/v5.1.1) with the following flags:
- DModule_ITKDCMTK:BOOL=ON
- DModule_ITKIODCMTK:BOOL=ON
- DBUILD_SHARED_LIBS:BOOL=ON
- ITKIOTransformDCMTK: [`github-actions`](https://github.com/mseng10/ITKIOTransformDCMTK/tree/github-actions)
- Forked branch

### Environment

- OS/Environment: [`Windows-2019`](https://github.com/actions/virtual-environments/blob/main/images/win/Windows2019-Readme.md)
- Python `3.7`
- CMake `3.18.4`
- Ninja `1.10.0.post2`

### Closing Remarks

Overall I am having issues finding the source of the issue in `DCMTK` build. If anyone can provide any help it would be greatly appreciated. Please let me know if anymore information needs to be provided. Also, here is a [link](https://docs.microsoft.com/en-us/cpp/error-messages/compiler-warnings/compiler-warning-c4335?view=msvc-160) to more information on the warning.