python: Fix at sign decorator highlighting conflict with matrix multiplication at sign operator (#58077)

In the current Python Tree-sitter `highlight.scm`, the `@` used for
decorators (`@punctuation.special` rule) is incorrectly overridden by
the `@` used for matrix multiplication (`@operator` rule).

This PR updates the matrix multiplication highlight query so it only
applies in binary operator contexts, and it also removes a duplicate
`@punctuation.special` for the `@` decorator.

| Before | After |
|
:---------------------------------------------------------------------------------------------------------------------------------:
|
:--------------------------------------------------------------------------------------------------------------------------------:
|
| <img width="338" height="1056" alt="image"
src="https://github.com/user-attachments/assets/cdce1556-6f7d-4542-abca-bcb3e11b6629"
/>| <img width="380" height="1057" alt="image"
src="https://github.com/user-attachments/assets/f948413c-ad8a-4ccc-89c1-bbffbe2affda"
/>|


Self-Review Checklist:

- [x] I've reviewed my own diff for quality, security, and reliability
- [x] Unsafe blocks (if any) have justifying comments
- [x] The content is consistent with the [UI/UX
checklist](https://github.com/zed-industries/zed/blob/main/CONTRIBUTING.md#uiux-checklist)
- [ ] Tests cover the new/changed behavior
- [x] Performance impact has been considered and is acceptable

Release Notes:

- Fix Python at sign decorator highlighting conflict with matrix
multiplication at sign operator

---------

Co-authored-by: Finn Evers <finn@zed.dev>

crates/grammars/src/python/highlights.scm

@@ -46,18 +46,17 @@
   function: (identifier) @function.call)
 
 (decorator
-  "@" @punctuation.special)
-
-(decorator
-  "@" @punctuation.special
+  "@" @function.decorator
   [
     (identifier) @function.decorator
     (attribute
+      object: (identifier) @function.decorator
       attribute: (identifier) @function.decorator)
     (call
       function: (identifier) @function.decorator.call)
     (call
       (attribute
+        object: (identifier) @function.decorator.call
         attribute: (identifier) @function.decorator.call))
   ])
 
@@ -257,7 +256,6 @@
   "&"
   "%"
   "%="
-  "@"
   "^"
   "+"
   "->"
@@ -282,6 +280,9 @@
   "|="
 ] @operator
 
+(binary_operator
+  operator: "@" @operator)
+
 [
   "and"
   "in"
@@ -335,8 +336,9 @@
 ] @keyword.definition
 
 (decorator
-  (identifier) @attribute.builtin
-  (#any-of? @attribute.builtin "classmethod" "staticmethod" "property"))
+  "@" @attribute.builtin
+  (identifier) @attribute.builtin @_decorator
+  (#any-of? @_decorator "classmethod" "staticmethod" "property"))
 
 (attribute
   attribute: (identifier) @attribute.special