[3.0] extras/tools: update meson to 0.56.2

The medialibrary that may be compiled in the VLC environment requires meson 0.56 at least.

Currently the minimum needed by all 3.0 contribs is 0.55 (harfbuzz).

We could also bump to 1.0.0 but we need to update the version check to have a minimum version of 1.0.0 as we don't all bump of the major versions on tools.