[mypyc] Implement bytes.endswith

[esarp]

Rounding out #20387 and implementing bytes.endswith. Simple benchmark shows a ~6.4x improvement.

Tested with the following benchmark code:

import time


def bench(suffix: bytes, a: list[bytes], n: int) -> int:
    i = 0
    for x in range(n):
        for b in a:
            if b.endswith(suffix):
                i += 1
    return i


a = [b"foo", b"barasdfsf", b"foobar", b"ab", b"asrtert", b"sertyeryt"]
n = 5 * 1000 * 1000
suffix = b"foo"

bench(suffix, a, n)

t0 = time.time()
bench(suffix, a, n)
td = time.time() - t0
print(f"{td}s")

Output:

$ python bench.py         
0.9002199172973633s
$ python -c "import bench"
0.13828086853027344s