Update dependencies and add dependabot config

Author: goneall

.github/dependabot.yml

@@ -0,0 +1,8 @@
+version: 2
+updates:
+  - package-ecosystem: "maven"
+    directory: "/"
+    schedule:
+      interval: "weekly"
+    labels:
+      - "dependencies"

pom.xml

@@ -118,7 +118,7 @@
     <dependency>
     	<groupId>com.google.code.gson</groupId>
     	<artifactId>gson</artifactId>
-    	<version>2.8.9</version>
+    	<version>2.13.2</version>
     </dependency>
     <dependency>
     	<groupId>junit</groupId>