[pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Author: pre-commit-ci[bot]

Diff for: greedy_methods/fractional_cover_problem.py

@@ -8,7 +8,7 @@ class Item:
     weight: int
     value: int
 
-    def __eq__(self, other: 'Item') -> bool:
+    def __eq__(self, other: "Item") -> bool:
         return self.weight == other.weight and self.value == other.value