README.md, asterisk.c: Update Copyright Dates

(cherry picked from commit d52cd705d3)

README.md

@@ -1,7 +1,7 @@
 # The Asterisk(R) Open Source PBX
 ```text
         By Mark Spencer <markster@digium.com> and the Asterisk.org developer community.
-        Copyright (C) 2001-2021 Sangoma Technologies Corporation and other copyright holders.
+        Copyright (C) 2001-2025 Sangoma Technologies Corporation and other copyright holders.
 ```
 ## SECURITY
 

main/asterisk.c

@@ -1,7 +1,7 @@
 /*
  * Asterisk -- An open source telephony toolkit.
  *
- * Copyright (C) 1999 - 2018, Digium, Inc.
+ * Copyright (C) 1999 - 2025, Sangoma Technologies Corporation
  *
  * Mark Spencer <markster@digium.com>
  *
@@ -53,7 +53,7 @@
  *
  * \section copyright Copyright and Author
  *
- * Copyright (C) 1999 - 2021, Sangoma Technologies Corporation.
+ * Copyright (C) 1999 - 2025, Sangoma Technologies Corporation.
  * Asterisk is a <a href="https://cdn.sangoma.com/wp-content/uploads/Sangoma-Trademark-Policy.pdf">registered trademark</a>
  * of <a rel="nofollow" href="http://www.sangoma.com">Sangoma Technologies Corporation</a>.
  *
@@ -297,7 +297,7 @@ int daemon(int, int);  /* defined in libresolv of all places */
 #define NUM_MSGS 64
 
 /*! Displayed copyright tag */
-#define COPYRIGHT_TAG "Copyright (C) 1999 - 2022, Sangoma Technologies Corporation and others."
+#define COPYRIGHT_TAG "Copyright (C) 1999 - 2025, Sangoma Technologies Corporation and others."
 
 /*! \brief Welcome message when starting a CLI interface */
 #define WELCOME_MESSAGE \