Update Jenkins core and fix related issues included dependencies conflicts and integration tests

[Cr1t-GYM]

• [x] jenkins core upgrades to 2.346.1
• [x] com.google.code.findbugs:jsr305 upgrades from 3.0.1 to 3.0.2
• [x] com.github.spotbugs:spotbugs-annotations upgrades from 4.4.1 to 4.6.0
• [x] net.sf.jopt-simple:jopt-simple upgrades from 5.0.2 to 5.0.4
• [x] com.google.code.gson:gson upgrades from 2.8.6 to 2.8.7
• [x] ugrade the building stage image from maven:3.6.3-adoptopenjdk-8 to maven:3.6.3-adoptopenjdk-11
• [x] fix integration test SmokeTest#checkoutSCM because newer core and git plugin don't allow local checkout

Some tests in other repository:

1. Build a SpringBoot project.
2. Lint a SpringBoot project and a React project. If we use the old core, this will fail at the pipeline initialization stage because of higher core requirement.
3. Feel free to preview the new image.