update assertj to newer version (OpenAPITools#22824)

Author: wing328

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

@@ -311,7 +311,7 @@
         {{/useJakartaEe}}
         <threetenbp-version>2.9.10</threetenbp-version>
         <maven-plugin-version>1.0.0</maven-plugin-version>
-        <assertj-version>3.23.1</assertj-version>
+        <assertj-version>3.27.7</assertj-version>
         <junit-version>5.10.2</junit-version>
     </properties>
 </project>

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

@@ -260,7 +260,7 @@
         <jakarta-annotation-version>1.3.5</jakarta-annotation-version>
         <threetenbp-version>2.9.10</threetenbp-version>
         <maven-plugin-version>1.0.0</maven-plugin-version>
-        <assertj-version>3.23.1</assertj-version>
+        <assertj-version>3.27.7</assertj-version>
         <junit-version>5.10.2</junit-version>
     </properties>
 </project>

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

@@ -260,7 +260,7 @@
         <jakarta-annotation-version>1.3.5</jakarta-annotation-version>
         <threetenbp-version>2.9.10</threetenbp-version>
         <maven-plugin-version>1.0.0</maven-plugin-version>
-        <assertj-version>3.23.1</assertj-version>
+        <assertj-version>3.27.7</assertj-version>
         <junit-version>5.10.2</junit-version>
     </properties>
 </project>