Update versions.json

Author: fabpot

.github/versions.json

@@ -736,6 +736,9 @@
             "6.2",
             "6.3"
         ],
+        "symfony/mailer-send-mailer": [
+            "6.3"
+        ],
         "symfony/mailgun-mailer": [
             "4.3",
             "4.4",
@@ -1030,6 +1033,9 @@
             "6.2",
             "6.3"
         ],
+        "symfony/pushover-notifier": [
+            "6.3"
+        ],
         "symfony/rate-limiter": [
             "5.2",
             "5.3",