[3.14] gh-129559: add bytearray.resize thread safety test for free-threading (GH-141739) (#141835)

[3.14] gh-129559: add `bytearray.resize` thread safety test for free-threading  (GH-141739)
(cherry picked from commit 019c315)

Author: cmaloney

Lib/test/test_bytes.py

@@ -2564,6 +2564,10 @@ def zfill(b, a):
             c = a.zfill(0x400000)
             assert not c or c[-1] not in (0xdd, 0xcd)
 
+        def resize(b, a):  # MODIFIES!
+            b.wait()
+            a.resize(10)
+
         def check(funcs, a=None, *args):
             if a is None:
                 a = bytearray(b'0' * 0x400000)
@@ -2625,6 +2629,8 @@ def check(funcs, a=None, *args):
         check([clear] + [startswith] * 10)
         check([clear] + [strip] * 10)
 
+        check([clear] + [resize] * 10)
+
         check([clear] + [contains] * 10)
         check([clear] + [subscript] * 10)
         check([clear2] + [ass_subscript2] * 10, None, bytearray(b'0' * 0x400000))