vtkWin32Header: mask the `STRICT` preprocessor token

It messes up in libproj where an enumeration has a `STRICT` variant.

Common/Core/vtkWin32Header.h

@@ -51,10 +51,11 @@ Do_not_include_vtkWin32Header_directly_vtkSystemIncludes_includes_it;
 // Windows specific stuff------------------------------------------
 #if defined(_WIN32)
 
-// define strict header for windows
-#ifndef STRICT
-#define STRICT
+// Define strict header for Windows (definition as itself ensures that no code breaks)
+#ifdef STRICT
+#undef STRICT
 #endif
+#define STRICT STRICT
 
 #ifndef NOMINMAX
 #define NOMINMAX

Documentation/release/dev/fix-explicit-ms-strict-macro.md

+# STRICT macro must not breaks libproj headers
+
+Previously, VTK defined the `STRICT` for `windows.h` as empty if it was not defined. This breaks the `Proj` project.
+
+The patch implements a workaround by `#define STRICT STRICT` to ensure that no codes breaks.
+
+```cpp
+#ifdef STRICT
+#undef STRICT
+#endif
+#define STRICT STRICT
+```