v13.1.0

@polarathene

Useful Links

Internal
- We now store the version that DMS is running on in the environment variable DMS_RELEASE and no longer in the file /VERSION. Moreover, the update check will use this to determine whether you are running :edge (to disable the update check if this is the case).
- An option to run DMS locally was added, and the docs saw improvements (as usual).
- The quota tests were adjusted and now conform to our new standards.
Documentation
- The troubleshooting documentation was enhanced.

Rspamd
- The ARM64 build now also uses the official PPA, making the version even for ARM64 and AMD64.
Dovecot
- The environment variable ENABLE_IMAP was added, which works analogous to ENABLE_POP3.

Internal
- A sed line for quota-related changes to Postfix's main.cf was not working as expected. This has been taken care of.

fix: Logging - Welcome should use DMS_RELEASE ENV by @polarathene in #3676
ci: Add run-local-instance target to Makefile by @georglauterbach in #3663
docs: Troubleshooting - Bare domain misconfiguration by @polarathene in #3680
chore: Postfix should integrate Dovecot at runtime by @polarathene in #3681
Add warning, when update-check is enabled, but no stable release image is used by @casperklein in #3684
scripts: Install arm64 rspamd from official repository by @p3dda in #3686
update-check: fix 'read' exit status by @casperklein in #3688
fix: only set virtual_mailbox_maps to texthash when not using LDAP by @reneploetz in #3693
Add ENV ENABLE_IMAP by @casperklein in #3703
tests(refactor): Dovecot quotas by @polarathene in #3068
ci: Avoiding linting CONTRIBUTORS.yml by @polarathene in #3705
ci: Allow lint workflow to be manually triggered by @polarathene in #3714
ci: Remove VERSION from Dockerfile by @polarathene in #3711
fix: sed logic for ENABLE_QUOTAS=0 is not actionable by @casperklein in #3715