Remove redundant "const" from wxItemId conversion operator

This "const" is ignored and just results in a warning from MSVS 17.6.

See #23590.

(cherry picked from commit 946aa6bbc430302265aea41754c13729f931edf4)

docs/changes.txt

@@ -235,6 +235,10 @@ Changes in behaviour which may result in build errors
 3.2.4: (released 2024-??-??)
 ----------------------------
 
+wxMSW:
+
+- Fix MSVS warning about redundant "const" in wx/itemid.h (#23590).
+
 
 3.2.3: (released 2023-10-10)
 ----------------------------

include/wx/itemid.h

@@ -33,7 +33,7 @@ public:
 
     bool IsOk() const { return m_pItem != NULL; }
     Type GetID() const { return m_pItem; }
-    operator const Type() const { return m_pItem; }
+    operator Type() const { return m_pItem; }
 
     // This is used for implementation purposes only.
     Type operator->() const { return m_pItem; }