meson: bump required glvnd version

https://github.com/KhronosGroup/EGL-Registry/pull/95 has moved
a couple of extensions defines and functions to the upstream `eglext.h`,
but when 9a74746bd1f3bd28d4c4 sync'ed these files we broke compilation
of apps that require these symbols on systems that don't have the
updated Khronos headers.

On non-GLVND builds, we still provide these headers, so everything's
fine, but on GLVND builds the Khronos headers are external so we need to
make sure we have a libglvnd version that's recent enough.

Fixes: 9a74746bd1f3bd28d4c4 ("EGL: sync headers with Khronos")
Signed-off-by: Eric Engestrom <eric@engestrom.ch>
Acked-by: Daniel Stone <daniels@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/6069>
3 files changed