gh-148675: Reuse typecodes for array.array() error message

[vstinner]

array.array() error message now reuses array.typecodes, instead of maintaining an hardcoded list of valid type codes.

• Issue: Add support for numpy buffer format Zf and Zd #148675

[vstinner]

Example:

import array
array.array('v')

Output:

Traceback (most recent call last):
  File "/home/vstinner/python/main/x.py", line 2, in <module>
    array.array('v')
    ~~~~~~~~~~~^^^^^
ValueError: bad typecode (must be: b, B, u, w, h, H, i, I, l, L, q, Q, e, f, d, Zf, Zd)

[vstinner]

Merged, thanks for the review.

I wrote this change since recently, I noticed that 3 type codes were missing from this error message. I fixed the error message, but with this change it's no longer neeeded (it's always up to date).