Log Message:
openttd: Update to 12.2

upstream changes:
-----------------
  * 12.2 (2022-04-02)
    [https://cdn.openttd.org/openttd-releases/12.2/changelog.txt]
  * 12.1 (2021-11-08)
    [https://cdn.openttd.org/openttd-releases/12.1/changelog.txt]
  * 12.0 (2021-10-17)
    [https://cdn.openttd.org/openttd-releases/12.0/changelog.txt]
  * 12.0-RC1 (2021-09-25)
  * 12.0-beta2 (2021-08-19)
  * 12.0-beta1 (2021-08-15)
  * 1.11 release series followed up by 12.0

pkgsrc changes:
---------------
  * Update GCC_REQD to 8 for std::charconv.