ci(cxx-python): fix commit reference

To address:

  Invalid workflow file: .github/workflows/cxx-python.yml#L17
  invalid value workflow reference: too many '@' in workflow reference

Author: thewtex

.github/workflows/cxx-python.yml

@@ -14,7 +14,7 @@ env:
 jobs:
   cxx-build-workflow:
     # itk-wasm branch
-    uses: thewtex/ITKRemoteModuleBuildTestPackageAction/.github/workflows/build-test-cxx.yml@l@6868c9879405def5d7532e0437b57e78cbe0b6ea
+    uses: thewtex/ITKRemoteModuleBuildTestPackageAction/.github/workflows/build-test-cxx.yml@6868c9879405def5d7532e0437b57e78cbe0b6ea
     with:
       itk-module-deps: '[email protected]'
       ctest-options: '-E itkPipelineTest'