Fix Windows build

Author: martinRenou

.github/workflows/main.yml

@@ -36,6 +36,12 @@ jobs:
     - name: Make build directory
       run: mkdir build
 
+    - name: Micromamba shell hook
+      if: matrix.os == 'windows-latest'
+      shell: powershell
+      run: |
+        micromamba shell hook -s cmd.exe -p C:\Users\runneradmin\micromamba-root
+
     - name: Unix, install
       if: matrix.os != 'windows-latest'
       run: |
@@ -46,9 +52,9 @@ jobs:
 
     - name: Windows, install
       if: matrix.os == 'windows-latest'
-      shell: cmd /C call {0}
+      shell: cmd
       run: |
-        micromamba activate pybind11_json
+        call C:\Users\runneradmin\micromamba-root\condabin\micromamba.bat activate pybind11_json
         cmake -G "NMake Makefiles" -D CMAKE_INSTALL_PREFIX="%CONDA_PREFIX%\Library" -D DOWNLOAD_GTEST=ON -D PYTHON_EXECUTABLE=%CONDA_PREFIX%/python.exe -Dgtest_force_shared_crt=ON -DCMAKE_CXX_FLAGS=/D_SILENCE_TR1_NAMESPACE_DEPRECATION_WARNING ..
         nmake install
       working-directory: build
@@ -62,8 +68,8 @@ jobs:
 
     - name: Windows, Run tests
       if: matrix.os == 'windows-latest'
-      shell: cmd /C call {0}
+      shell: cmd
       run: |
-        micromamba activate pybind11_json
+        call C:\Users\runneradmin\micromamba-root\condabin\micromamba.bat activate pybind11_json
         ./test/test_pybind11_json
       working-directory: build