with gir now moved in private path should not be needed

gir files don't contain arch specific path so is possible have them in
cinnamon-common.
This also decrease differences with upstream packages

this will avoid add of -dev deps in cinnamon package

Like gnome-shell where forked gir files should be in private path

This reverts commit 9eb69f14.

Thanks: Simon McVittie
Closes: #1050801

Closes: #1051210

from a fast search seems don't used anymore

https://lintian.debian.org/tags/gir-in-arch-all-package
GObject-Introspection XML files (/usr/share/gir-1.0/Foo-23.gir) must be
made available in an architecture-dependent package of the same source.

Update to upstream version '5.8.4'
with Debian dir 6f19f6593b477ef24d546674b987eada8480c075

is not in debian repository but is present in ubuntu

needed for new use of switcheroo for gpu offloading
https://github.com/linuxmint/cinnamon/commit/00b0a65bd47d805b7bdbfcc4723f3d43ac1ea116

upstream added it as depends but seems to me is better in recommends as
only part of users use flatpak packages

https://github.com/linuxmint/cinnamon/commit/7e211e2e251b2df0d80b386cc6de2ebc3db21e5f

we don't add -dev package as cinnamon not really needed it for build
others things, only .gir files can be useful in some cases so add them
in -common like gnome-shell

Update to upstream version '5.8.3'
with Debian dir 41c209d1bc51ec234c07f5be420cb4ace074b19c