Bump version to 5.3.0

C++17 modernization, Tor v2 removal, embedded Tor scaffold, IBD speedups.

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>

src/clientversion.h

@@ -7,8 +7,8 @@
 
 // These need to be macros, as version.cpp's and triangles-qt.rc's voodoo requires it
 #define CLIENT_VERSION_MAJOR       5
-#define CLIENT_VERSION_MINOR       2
-#define CLIENT_VERSION_REVISION    1
+#define CLIENT_VERSION_MINOR       3
+#define CLIENT_VERSION_REVISION    0
 #define CLIENT_VERSION_BUILD       0
 
 // Converts the parameter X to a string after macro replacement on X has been performed.

src/version.h

@@ -52,8 +52,8 @@ static const int BIP0031_VERSION = 60000;
 static const int MEMPOOL_GD_VERSION = 60002;
 
 #define DISPLAY_VERSION_MAJOR       5
-#define DISPLAY_VERSION_MINOR       2
-#define DISPLAY_VERSION_REVISION    1
+#define DISPLAY_VERSION_MINOR       3
+#define DISPLAY_VERSION_REVISION    0
 #define DISPLAY_VERSION_BUILD       0
 
 #endif