Update dependency versions in README.md

Upgraded solanaj-programs and phoenix dependencies from version 1.30.3 to 1.31.0. This ensures the documentation reflects the latest changes and improvements in the dependencies.

README.md

@@ -10,15 +10,15 @@ Bonfida.
 <dependency>
         <groupId>com.mmorrell</groupId>
         <artifactId>solanaj-programs</artifactId>
-        <version>1.30.3</version>
+        <version>1.31.0</version>
 </dependency>
 ```
 Or just one dependency:
 ```xml
 <dependency>
     <groupId>com.mmorrell</groupId>
     <artifactId>phoenix</artifactId>
-    <version>1.30.3</version>
+    <version>1.31.0</version>
 </dependency>
 ```