update resteasy lib to newer version (#12688)

Author: wing328

modules/openapi-generator/src/main/resources/Java/libraries/resteasy/pom.mustache

@@ -273,7 +273,7 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <swagger-annotations-version>1.6.3</swagger-annotations-version>
-        <resteasy-version>4.5.11.Final</resteasy-version>
+        <resteasy-version>4.7.6.Final</resteasy-version>
         <jackson-version>2.10.5</jackson-version>
         <jackson-databind-version>2.10.5.1</jackson-databind-version>
         {{#openApiNullable}}

samples/client/petstore/java/resteasy/pom.xml

@@ -254,7 +254,7 @@
     <properties>
         <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding>
         <swagger-annotations-version>1.6.3</swagger-annotations-version>
-        <resteasy-version>4.5.11.Final</resteasy-version>
+        <resteasy-version>4.7.6.Final</resteasy-version>
         <jackson-version>2.10.5</jackson-version>
         <jackson-databind-version>2.10.5.1</jackson-databind-version>
         <jackson-databind-nullable-version>0.2.2</jackson-databind-nullable-version>