Migrate Infrastructure

[timonmasberg]

Due to Microsoft reducing the annual grant in the Azure Sponsorship program, we cannot fully host our application stack on Azure anymore. We need to immediately migrate to a self-hosted solution...

• [x] evaluate which solution we want to use for our cluster (microk8s, k3s, k0s are popular solutions)
• [x] setup k8s on the server
• [x] setup infra repo @JSPRH
• [x] Build, tag and publish image in pipeline @JSPRH
• [x] migrate CI/CD towards server new infra (next and prod deployment, next E2Es, fix #329) @timonmasberg
• [x] ensure that our infrastructure is easily maintainable and described in a way that we can easily spin it up somewhere else (https://github.com/kordis-leitstelle/kordis/issues/138, thus we probably need to set up https://github.com/kordis-leitstelle/kordis/issues/176 for our k8s configs) @JSPRH
• [x] setup next and prod environments, ensure option for dynamic environment creation (preview environments)
• [x] set the auth strategy in the AuthModule to aadb2c
• [ ] update documentation, especially the landscape, write ADR on why we had to move to a bare-metal solution
• [x] spin down every azure resource we are not going to need anymore
• [ ] Backup strategy (kubernetes volumes snapshot)
• [ ] harden server

[JSPRH]

Our new infrastructure repo (private) is here! https://github.com/kordis-leitstelle/infrastructure