ICU-23290 BRS_78_2_GA Update version number to 78.2 (no SNAPSHOT / rc)

[mihnita]

Checklist

• Required: Issue filed: ICU-23290
• Required: The PR title must be prefixed with a JIRA Issue number. Example: "ICU-NNNNN Fix xyz"
• Required: Each commit message must be prefixed with a JIRA Issue number. Example: "ICU-NNNNN Fix xyz"
• Issue accepted (done by Technical Committee after discussion)
• Tests included, if applicable
• API docs and/or User Guide docs changed or added, if applicable
• Approver: Feel free to merge on my behalf

[mihnita]

Rich and Elango are required to approve, or they are only to be in the loop?
In other words, when the tests pass can I merge, or I need to wait?

[markusicu]

Rich and Elango are required to approve, or they are only to be in the loop? In other words, when the tests pass can I merge, or I need to wait?

I like to add multiple people for awareness, and in case they spot something that I don't.
If tests pass and they don't chime in, you can merge.