Fix test_comments() in test_source

Copied the test as fixed in pytest's repo.

testing/code/test_source.py

@@ -497,7 +497,7 @@ def test_oneline_and_comment():
     source = getstatement(0, "raise ValueError\n#hello")
     assert str(source) == "raise ValueError"
 
-def test_comments():
+def test_comments() -> None:
     source = '''def test():
     "comment 1"
     x = 1
@@ -510,11 +510,17 @@ def test_comments():
 comment 4
 """
 '''
-    for line in range(2,6):
-        assert str(getstatement(line, source)) == '    x = 1'
-    for line in range(6,10):
-        assert str(getstatement(line, source)) == '    assert False'
-    assert str(getstatement(10, source)) == '"""'
+    for line in range(2, 6):
+        assert str(getstatement(line, source)) == "    x = 1"
+    if sys.version_info >= (3, 8) or hasattr(sys, "pypy_version_info"):
+        tqs_start = 8
+    else:
+        tqs_start = 10
+        assert str(getstatement(10, source)) == '"""'
+    for line in range(6, tqs_start):
+        assert str(getstatement(line, source)) == "    assert False"
+    for line in range(tqs_start, 10):
+        assert str(getstatement(line, source)) == '"""\ncomment 4\n"""'
 
 def test_comment_in_statement():
     source = '''test(foo=1,