[Feature]: Automate release steps

[yurishkuro]

Requirement

We would like to simplify the release process.

Problem

Right now the release involves a number of manual steps, e.g. in the second section of this issue: #7496

Proposal

Similar to jaegertracing/jaeger-ui#3056, automate the manual steps:

• automate creation of PR with changelog and UI upgrade
• automate pushing tags (print commands to be executed for user to confirm)

The last two steps (creating release and kicking off artifacts building workflow) can remain manual for now.

The overall release process would be:

1. run release/start.sh which creates a PR with instructions / steps similar to Prepare Jaeger Release v1.73.0 / v2.10.0 #7496. In those instructions all versions should be pre-populated already, because start.sh determines them.
2. in the issue checklist the automated command for creating release would be something like "Run: bash ./scripts/release/prepare 1.x.x 2.x.x (with concrete versions).