SNI integration tests are not using configured repositories

[snicoll]

#26022 has introduced additional integration tests that configure a number of repositories for each test, for example:

spring-boot/spring-boot-tests/spring-boot-integration-tests/spring-boot-sni-tests/spring-boot-sni-client-app/settings.gradle

Lines 2 to 7 in c63eba3

	repositories {
	maven { url "file:${rootDir}/../int-test-maven-repository"}
	mavenCentral()
	maven { url "https://repo.spring.io/snapshot" }
	maven { url "https://repo.spring.io/milestone" }
	}

Unfortunately this doesn't match the repositories that the build configures, typically for commercial releases.