FXIOS-12868 - Update import-strings cron to run on Thursday (#28047)

FXIOS-12868 - Update import-strings cron to run on Monday

Author: dsmithpadilla

.github/workflows/firefox-ios-import-strings.yml

@@ -1,7 +1,7 @@
 name: "Firefox: import translations"
 on:
   schedule:
-    - cron: '0 11 * * 1'
+    - cron: '0 11 * * 4'
   workflow_dispatch:
     inputs:
       branchName: