pretix: compile all languages at build time

Pretix wants to build locales according to the user configuration, which
does not exist in our case and leads to certain languages not being
built.

As our packages are immutable, the user config will never be able to
influence them and we therefore must enable all languages at build time.

Closes: #297708

pkgs/by-name/pr/pretix/language-build.patch

@@ -0,0 +1,12 @@
+diff --git a/src/pretix/_build_settings.py b/src/pretix/_build_settings.py
+index d1ea73b84..9e13cdc87 100644
+--- a/src/pretix/_build_settings.py
++++ b/src/pretix/_build_settings.py
+@@ -49,6 +49,7 @@ HAS_MEMCACHED = False
+ HAS_CELERY = False
+ HAS_GEOIP = False
+ SENTRY_ENABLED = False
++LANGUAGES = ALL_LANGUAGES
+ 
+ for entry_point in entry_points(group='pretix.plugin'):
+     INSTALLED_APPS.append(entry_point.module) # noqa: F405

pkgs/by-name/pr/pretix/package.nix

@@ -67,6 +67,10 @@ python.pkgs.buildPythonApplication rec {
     # INSTALLED_APPS, so that their static files are collected.
     ./plugin-build.patch
 
+    # Configure django-statici18n to compile all available languages at
+    # build time.
+    ./language-build.patch
+
     (fetchpatch2 {
       # Allow customization of cache and log directory
       # https://github.com/pretix/pretix/pull/3997