Merge #150: make-tag: remove pre 22.x script

d6c2b8d make-tag: remove pre 22.x script (fanquake)

Pull request description:

  The final 0.21 tag has been made. See: https://github.com/bitcoin/bitcoin/releases/tag/v0.21-final.

ACKs for top commit:
  achow101:
    ACK d6c2b8d
  hebasto:
    ACK d6c2b8d

Tree-SHA512: ccbcaed8eae8fb08912655acabc2df121b436034f535a9b8463343e54935336eae5c00097d1c424e9e5d2e2d59cd4a6a4c23a5c61f92a03b0e62f48431467f1c

Author: fanquake