gh-36517: `sage.misc.lazy_attribute`: Add typestub file for pyright
    
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Split out from #36443 to facilitate review.

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URL: #36517
Reported by: Matthias Köppe
Reviewer(s): Tobias Diez

Author: Release Manager

src/sage/misc/lazy_attribute.pyi

@@ -0,0 +1,9 @@
+# This type-stub file helps pyright understand the decorator @lazy_attribute.
+
+# Adapted from https://github.com/python/typeshed/blob/b9640005eb586afdbe0a57bac2b88a7a12465069/stdlib/builtins.pyi#L1237-L1254
+class lazy_attribute:
+    def __init__(
+        self,
+        f: Callable[[Any], Any] | None = ...
+    ) -> None: ...
+    def __get__(self, a: Any, cls: type) -> Any: ...