* deps: update some dependencies to fix warnings
* chore: move from sl.local to sl.lan for local development
* fix: mark string as regex
* chore: move facebook import to handler so its not global
* test: fix tests
* style: lint fixes
* test: move all .test and .local to .lan
* ci: do not use setup-python in lint
* Send email to users with a subscription and a partner plan upgrade
* Update double-subscription-partner.html
* Update double-subscription-partner.txt.jinja2
Co-authored-by: Adrià Casajús <adria.casajus@proton.ch>
Co-authored-by: Son Nguyen Kim <nguyenkims@users.noreply.github.com>