chore: update milestones after 31.0.7 & 30.0.13

Signed-off-by: skjnldsv <skjnldsv@protonmail.com>

Author: skjnldsv

milestoneupdater/config.json

@@ -31,9 +31,9 @@
   ],
   "dueDates": {
     "Nextcloud 30.0.13": "2025-07-10",
-    "Nextcloud 30.0.14": "2025-07-10",
-    "Nextcloud 31.0.7": "2025-08-07",
-    "Nextcloud 31.0.8": "2025-08-07"
+    "Nextcloud 30.0.14": "2025-08-14",
+    "Nextcloud 31.0.7": "2025-07-10",
+    "Nextcloud 31.0.8": "2025-08-14"
   },
   "closeMilestones": [
     "Nextcloud 31.0.7",