Update version to avoid confusions...

...considering that `raylib 5.5` official release could still take some time...

src/raylib.h

@@ -84,7 +84,7 @@
 #define RAYLIB_VERSION_MAJOR 5
 #define RAYLIB_VERSION_MINOR 5
 #define RAYLIB_VERSION_PATCH 0
-#define RAYLIB_VERSION  "5.5"
+#define RAYLIB_VERSION  "5.5-dev"
 
 // Function specifiers in case library is build/used as a shared library
 // NOTE: Microsoft specifiers to tell compiler that symbols are imported/exported from a .dll