[GRASS-git] [OSGeo/grass] e53572: Use GRASS version for non-git builds. (#2636)

[Bas Couwenberg]

  Branch: refs/heads/releasebranch_8_2
  Home:   https://github.com/OSGeo/grass
  Commit: e5357245be7d98c97fa4b20e71887b5123a73293
      https://github.com/OSGeo/grass/commit/e5357245be7d98c97fa4b20e71887b5123a73293
  Author: Bas Couwenberg <sebastic at xs4all.nl>
  Date:   2022-11-12 (Sat, 12 Nov 2022)

  Changed paths:
    M configure
    M configure.ac

  Log Message:
  -----------
  Use GRASS version for non-git builds. (#2636)

As reported in #2610, rebuilding the GRASS sources (from the release tarballs) with no changes break the gdal-grass plugins because the `GIS_H_VERSION` value changes.

Non-git builds use the current timestamp in `GRASS_HEADERS_GIT_HASH` which is also used for `GRASS_HEADERS_DATE`.

This PR uses `GRASS_VERSION_NUMBER` for `GRASS_HEADERS_GIT_HASH` as a better value for non-git builds, that value won't change for simple rebuilds of the source tree.