Bump org.testcontainers:testcontainers-bom from 1.20.2 to 1.20.3

Bumps [org.testcontainers:testcontainers-bom](https://github.com/testcontainers/testcontainers-java) from 1.20.2 to 1.20.3.
- [Release notes](https://github.com/testcontainers/testcontainers-java/releases)
- [Changelog](https://github.com/testcontainers/testcontainers-java/blob/main/CHANGELOG.md)
- [Commits](testcontainers/testcontainers-java@1.20.2...1.20.3)

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

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

Author: dependabot[bot]

chapter-4/chapter-4-spring-data-jpa/pom.xml

@@ -15,7 +15,7 @@
 	<description>Spring Data JPA example</description>
 	<properties>
 		<java.version>11</java.version>
-		<testcontainers.version>1.20.2</testcontainers.version>
+		<testcontainers.version>1.20.3</testcontainers.version>
 	</properties>
 	<dependencyManagement>
 		<dependencies>

chapter-4/chapter-4-spring-data-r2dbc/pom.xml

@@ -15,7 +15,7 @@
 	<description>Spring Data R2DBC example</description>
 	<properties>
 		<java.version>11</java.version>
-		<testcontainers.version>1.20.2</testcontainers.version>
+		<testcontainers.version>1.20.3</testcontainers.version>
 	</properties>
 	<dependencyManagement>
 		<dependencies>

chapter-5/chapter-5-spring-kafka-streams/pom.xml

@@ -15,7 +15,7 @@
 	<properties>
 		<java.version>11</java.version>
 		<spring-cloud.version>2021.0.9</spring-cloud.version>
-		<testcontainers.version>1.20.2</testcontainers.version>
+		<testcontainers.version>1.20.3</testcontainers.version>
 	</properties>
 	<dependencyManagement>
 		<dependencies>