Previously, some tests in spring-context wrote a file named jmx.log
into spring-context/. This led to the file being included in the
sources of the Checkstyle NoHTTP Gradle task, breaking that task's
UP-TO-DATE checks and causing it to execute unnecessarily.
This commit updates the tests to write the jmx.log file beneath
spring-context/build/ so that it is not included in the sources of the
Checkstyle NoHTTP task.
Closes gh-23623