build(deps): Bump org.testcontainers:postgresql in /sample-apps/jdbc-app

Bumps [org.testcontainers:postgresql](https://github.com/testcontainers/testcontainers-java) from 1.20.3 to 1.20.4.
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](testcontainers/testcontainers-java@1.20.3...1.20.4)

---
updated-dependencies:
- dependency-name: org.testcontainers:postgresql
  dependency-type: direct:production
  update-type: version-update:semver-patch
...

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

sample-apps/jdbc-app/build.gradle

@@ -10,7 +10,7 @@ dependencies {
     api 'jakarta.platform:jakarta.jakartaee-api:10.0.0'
     api 'org.eclipse.microprofile:microprofile:7.0'
 
-    testImplementation 'org.testcontainers:postgresql:1.20.3'
+    testImplementation 'org.testcontainers:postgresql:1.20.4'
     testImplementation 'org.slf4j:slf4j-log4j12:2.0.16'
     testImplementation 'org.junit.jupiter:junit-jupiter:5.11.3'