Fix tagged test platform sort order

Author: Ariouz

graalpython/com.oracle.graal.python.test/src/runner.py

@@ -1242,7 +1242,7 @@ def is_platform_excluded(self, key: str) -> bool:
 
     def get_keys_as_str(self) -> list[str]:
         keys = []
-        for key in self.keys:
+        for key in sorted(self.keys):
             keys.append(key if key not in self.excluded_keys else f"${key}")
         return keys
 
@@ -1252,7 +1252,7 @@ def __str__(self):
             s += '!'
         s += self.test_id.test_name
         if self.keys:
-            s += f' @ {",".join(sorted(self.get_keys_as_str()))}'
+            s += f' @ {",".join(self.get_keys_as_str())}'
         if self.comment:
             s = f'{self.comment}{s}'
         return s