Agent base java 21, jdk agent java 25 & springboot QS update#1156

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BraisVQ wants to merge 12 commits intomasterfrom

feature/update-jenkins-java21

Commits on Apr 1, 2026

add warning for subprocess execution in Java version switch scripts
BraisVQ
committed
add warnings for subprocess execution in Java version switch scripts and update script syntax for consistency
BraisVQ
committed
update Dockerfiles to use 'source' for script execution in JDK test commands
BraisVQ
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