docs: fix grammar in tests/shanghai

repo_subpaths_for_grammar_check.md

@@ -14,7 +14,7 @@ Status legend: `[ ]` pending, `[~]` in progress, `[x]` complete
 - [x] `tests/osaka/**/*.py` (~43 files)
 - [x] `tests/benchmark/**/*.py` (~36 files)
 - [x] `tests/json_infra/**/*.py` (~22 files)
-- [ ] `tests/shanghai/**/*.py` (~19 files)
+- [x] `tests/shanghai/**/*.py` (~19 files)
 - [ ] `tests/byzantium/**/*.py` (~11 files)
 - [ ] `tests/istanbul/**/*.py`, `berlin/**/*.py` (~18 files)
 - [ ] `tests/constantinople/**/*.py`, `amsterdam/**/*.py` (~16 files)

tests/shanghai/eip4895_withdrawals/test_withdrawals.py

@@ -300,11 +300,13 @@ def test_withdrawals_root(
 @pytest.mark.parametrize("test_case", ["single_block", "multiple_blocks"])
 class TestMultipleWithdrawalsSameAddress:
     """
-    Test that multiple withdrawals can be sent to the same address in.
+    Test that multiple withdrawals can be sent to the same address.
 
-    1. A single block.
+    1. `single_block`: Test multiple withdrawals to the same address in a
+    single block.
 
-    2. Multiple blocks.
+    2. `multiple_blocks`: Test multiple withdrawals to the same address across
+    multiple blocks.
     """
 
     @pytest.fixture