[ty] Add support for @warnings.deprecated (#19376)

* [x] basic handling
  * [x] parse and discover `@warnings.deprecated` attributes
  * [x] associate them with function definitions
  * [x] associate them with class definitions
  * [x] add a new "deprecated" diagnostic
* [x] ensure diagnostic is styled appropriately for LSPs
(DiagnosticTag::Deprecated)

* [x] functions
  * [x] fire on calls
  * [x] fire on arbitrary references 
* [x] classes
  * [x] fire on initializers
  * [x] fire on arbitrary references
* [x] methods
  * [x] fire on calls
  * [x] fire on arbitrary references
* [ ] overloads
  * [ ] fire on calls
  * [ ] fire on arbitrary references(??? maybe not ???)
  * [ ] only fire if the actual selected overload is deprecated 

* [ ] dunder desugarring (warn on deprecated `__add__` if `+` is
invoked)
* [ ] alias supression? (don't warn on uses of variables that deprecated
items were assigned to)

* [ ] import logic
  * [x] fire on imports of deprecated items
* [ ] suppress subsequent diagnostics if the import diagnostic fired (is
this handled by alias supression?)
  * [x] fire on all qualified references (`module.mydeprecated`)
  * [x] fire on all references that depend on a `*` import
    


Fixes https://github.com/astral-sh/ty/issues/153

crates/ty_python_semantic/src/module_resolver/module.rs

@@ -275,6 +275,7 @@ pub enum KnownModule {
     UnittestMock,
     #[cfg(test)]
     Uuid,
+    Warnings,
 }
 
 impl KnownModule {
@@ -294,6 +295,7 @@ impl KnownModule {
             Self::TypeCheckerInternals => "_typeshed._type_checker_internals",
             Self::TyExtensions => "ty_extensions",
             Self::ImportLib => "importlib",
+            Self::Warnings => "warnings",
             #[cfg(test)]
             Self::UnittestMock => "unittest.mock",
             #[cfg(test)]