Bump antlr4 from 4.9.2 to 4.9.3 in /data-prepper-expression (#1289)

Bumps [antlr4](https://github.com/antlr/antlr4) from 4.9.2 to 4.9.3.
- [Release notes](https://github.com/antlr/antlr4/releases)
- [Changelog](https://github.com/antlr/antlr4/blob/master/CHANGES.txt)
- [Commits](antlr/antlr4@4.9.2...4.9.3)

---
updated-dependencies:
- dependency-name: org.antlr:antlr4
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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data-prepper-expression/build.gradle

@@ -13,7 +13,7 @@ ext {
 }
 
 dependencies {
-    antlr 'org.antlr:antlr4:4.9.2'
+    antlr 'org.antlr:antlr4:4.9.3'
     implementation project(':data-prepper-api')
     implementation 'javax.inject:javax.inject:1'
     implementation('org.springframework:spring-core:5.3.13') {