gplugin/gplugin

Bump the minimum meson to 0.61.0 and clean up some warnings

2022-04-18, Gary Kramlich
55291fd09e7d
Bump the minimum meson to 0.61.0 and clean up some warnings

Testing Done:
Compiled.

Reviewed at https://reviews.imfreedom.org/r/1350/
// SPDX-FileCopyrightText: 2021 GNOME Foundation
// SPDX-License-Identifier: LGPL-2.1-or-later
// A map between namespaces and base URLs for their online documentation
baseURLs = [
[ 'GLib', 'https://docs.gtk.org/glib/' ],
[ 'GObject', 'https://docs.gtk.org/gobject/' ],
[ 'GModule', 'https://docs.gtk.org/gmodule/' ],
]