build(deps): bump io.gatling.gradle in /generators/server/resources

Bumps io.gatling.gradle from 3.12.0.3 to 3.12.0.4.

---
updated-dependencies:
- dependency-name: io.gatling.gradle
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

Signed-off-by: dependabot[bot] <[email protected]>

generators/server/resources/gradle/libs.versions.toml

@@ -40,6 +40,6 @@ gradle-enterprise = { id = 'com.gradle.enterprise', version = '3.18.1' }
 
 common-custom-user-data-gradle-plugin = { id = 'com.gradle.common-custom-user-data-gradle-plugin', version = '2.0.2' }
 
-gatling-gradle = { id = 'io.gatling.gradle', version = '3.12.0.3' }
+gatling-gradle = { id = 'io.gatling.gradle', version = '3.12.0.4' }
 
 gradle-openapi-generator = { id = 'org.openapi.generator', version = '7.9.0' }