docs: update developer manual

[miurahr]

Update release procedure to reflect recent CI/CD updates

Pull request type

• Documentation -> [documentation]

What does this PR change?

• Add mail template for pre-announce for dev list
• Merge procedures to deal JRE versions
• Merge test and integration test as one, and add description that these tests are done in Weekly release Ci/CD
• Remove old version contents
• Renumbering

Other information