misc: Update copyright years to 2023

CMakeLists.txt

README.md

build.py

extras/build/cmake/cmake_uninstall.cmake.in

extras/build/cmake/modules/FindLibJami.cmake

extras/ci/client-qt-gnulinux/Jenkinsfile

extras/data/jami.appdata.xml

extras/packaging/gnu-linux/Jenkinsfile

extras/packaging/gnu-linux/Makefile

extras/packaging/gnu-linux/guix/guix-pack-deb.postinst

extras/packaging/gnu-linux/guix/guix-pack-manifest.scm

extras/packaging/gnu-linux/rules/debian/copyright

extras/packaging/gnu-linux/rules/snap/jami/snapcraft.yaml

extras/packaging/gnu-linux/scripts/build-package-debian.sh

extras/packaging/gnu-linux/scripts/build-package-rpm.sh

extras/packaging/gnu-linux/scripts/build-package-snap.sh

extras/packaging/gnu-linux/scripts/deploy-packages.sh

...as/packaging/gnu-linux/scripts/prebuild-package-debian.sh

extras/scripts/format.sh

extras/scripts/gen_qml_qrc.py