GHA: re-enable Windows builds/tests.

src/bindings/python/CMakeLists.txt

@@ -52,7 +52,13 @@ if(LIBOPENCOR_PYTHON_BINDINGS)
     target_link_libraries(${PYTHON_BINDINGS_TARGET} PRIVATE
                           $<TARGET_NAME:${CMAKE_PROJECT_NAME}>)
 
-    if($ENV{GITHUB_ACTIONS} AND WIN32 AND SKBUILD)
+    if($ENV{GITHUB_ACTIONS})
+        set(GITHUB_ACTIONS ON)
+    else()
+        set(GITHUB_ACTIONS OFF)
+    endif()
+
+    if(GITHUB_ACTIONS AND WIN32 AND SKBUILD)
         # Note: this is to account for the fact that the `pip install libOpenCOR` step in our CI doesn't, on GitHub
         #       Actions' Windows runner, generate the library in the correct place while it used to be fine before (see
         #       https://github.com/actions/runner-images/issues/10004). Normally, we would expect the library to be