organization-select: clean up translations

packages/organization-select/src/i18n/de/translation.json

 {
   "select-organization": {
     "placeholder": "Bitte wählen Sie ein Institut aus",
-    "loading": "Wird geladen...",
-    "load-error": "Fehler beim Laden der Organisation"
+    "loading": "Wird geladen..."
   }
 }

packages/organization-select/src/i18n/en/translation.json

 {
   "select-organization": {
     "placeholder": "Please select an organization",
-    "loading": "Loading...",
-    "load-error": "Error loading the organization"
+    "loading": "Loading..."
   }
 }