Mark many attributes as read-only properties (#7591)

stubs/beautifulsoup4/bs4/builder/_html5lib.pyi

@@ -58,7 +58,8 @@ class Element(Any):  # html5lib.treebuilders.base.Node
     def cloneNode(self): ...
     def hasContent(self): ...
     def getNameTuple(self): ...
-    nameTuple: Any
+    @property
+    def nameTuple(self): ...
 
 class TextNode(Element):
     element: Any

stubs/beautifulsoup4/bs4/element.pyi

@@ -262,7 +262,8 @@ class Tag(PageElement):
     def __copy__(self: Self) -> Self: ...
     @property
     def is_empty_element(self) -> bool: ...
-    isSelfClosing = is_empty_element
+    @property
+    def isSelfClosing(self) -> bool: ...
     @property
     def string(self) -> str | None: ...
     @string.setter