Update CHANGELOG and release version 0.15.19

CHANGELOG.md

 # Changelog
 
+## [0.15.19] - 2023-12-20
+
+* Update nextcloud helm chart to v4.5.8.
+  - In particular this upgrades Nextcloud to 27.1.4.
+* Extend support for app pinning, by introducing a `raw_url` value for apps as
+  an alternative to github repo and version. This can be used for apps that are
+  not hosted on github (`passwords`), or ones that do not include the build
+  tarball as a release asset (`appointments`).
+* Add a helm test for checking that there are no disabled apps except the
+  expected ones. This helps to prevent accidentally disabling apps by upgrading
+  them to versions that are not compatible with the nextcloud version.
+
 ## [0.15.18] - 2023-11-01
 
 * Disable bulkupload, to prevent failures with the desktop client.

Chart.yaml

@@ -4,7 +4,7 @@ description: |
   A helm chart for installing NextCloud and setting up ONLYOFFICE integration
 name: nextcloud-onlyoffice
 appVersion: NC-27.1.4-OO-7.2.2.56
-version: 0.15.18
+version: 0.15.19
 icon: https://cdn.rawgit.com/docker-library/docs/defa5ffc7123177acd60ddef6e16bddf694cc35f/nextcloud/logo.svg
 dependencies:
   # https://artifacthub.io/packages/helm/nextcloud/nextcloud