build(deps): bump org.springframework.boot:spring-boot-dependencies

Bumps [org.springframework.boot:spring-boot-dependencies](https://github.com/spring-projects/spring-boot) from 3.5.7 to 4.0.0.
- [Release notes](https://github.com/spring-projects/spring-boot/releases)
- [Commits](spring-projects/spring-boot@v3.5.7...v4.0.0)

---
updated-dependencies:
- dependency-name: org.springframework.boot:spring-boot-dependencies
  dependency-version: 4.0.0
  dependency-type: direct:production
  update-type: version-update:semver-major
...

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

Author: dependabot[bot]

testcontainers-spring-boot-parent/pom.xml

@@ -15,7 +15,7 @@
     <description>Parent pom for all embedded testcontainers</description>
 
     <properties>
-        <spring.boot.version>3.5.7</spring.boot.version>
+        <spring.boot.version>4.0.0</spring.boot.version>
         <spring.cloud.version>2025.0.0</spring.cloud.version>
         <spring.cloud.gcp.version>7.4.1</spring.cloud.gcp.version>
         <equalsverifier.version>4.2.3</equalsverifier.version>