package/minetest{-game}: bump to version 5.3.0

package/minetest{-game}: bump to version 5.3.0

See Changelog [1]

Disable unittests build with the new BUILD_UNITTESTS option.

Update minetest-game licence file hash for:
  mods/default/license.txt [2]
  mods/farming/license.txt [3]

Update minetest license file hash for:
  LICENSE.txt [4]

[1] https://dev.minetest.net/Changelog#5.2.0_.E2.86.92_5.3.0
[2] https://github.com/minetest/minetest_game/commit/0662f962842b071525fa00ce970d8cc645bd68a4
[3] https://github.com/minetest/minetest_game/commit/e5a7af1c4abaf06ad764bf7c5da058fd136871c0
[4] https://github.com/minetest/minetest/commit/9a64a9fd9427fc3b62d4dc9bf1ca7c15477ebc5a

Signed-off-by: Romain Naour <romain.naour@gmail.com>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>