chore: translated using Weblate (German) (#2396)

Translated using Weblate (German)

Currently translated at 99.6% (312 of 313 strings)

Translation: memos-i18n/i18n
Translate-URL: https://hosted.weblate.org/projects/memos-i18n/english/de/

Co-authored-by: Frank Emmerlich <femmdi2012@gmail.com>

web/src/locales/de.json

@@ -112,7 +112,7 @@
   },
   "heatmap": {
     "day": "Tag",
-    "days": "Tage",
+    "days": "Tagen",
     "memo-in": "memo in {{period}}",
     "memo-on": "{{amount}} memo am {{date}}",
     "memos-in": "memos in {{period}}",