Bump fastjson from 1.2.4 to 1.2.83 in /chapter07

Bumps [fastjson](https://github.com/alibaba/fastjson) from 1.2.4 to 1.2.83.
- [Release notes](https://github.com/alibaba/fastjson/releases)
- [Commits](https://github.com/alibaba/fastjson/compare/1.2.4...1.2.83)

---
updated-dependencies:
- dependency-name: com.alibaba:fastjson
  dependency-type: direct:production
...
Signed-off-by: Ndependabot[bot] <support@github.com>

chapter07/pom.xml

@@ -77,7 +77,7 @@
         <dependency>
             <groupId>com.alibaba</groupId>
             <artifactId>fastjson</artifactId>
-            <version>1.2.4</version>
+            <version>1.2.83</version>
         </dependency>
 
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