fix: adjust prod release flow to support release branch lookup

[jon-funk]

Description

Adjusts and renames the prior merge to main release workflow from a push based workflow to exclusively workflow_dispatch. release_branch is required and is used to lookup the latest PR on the targeted release branch.

Note: workflow_dispatch based workflows unfortunately cannot be run until they are merged into main so testing this with the UI user input will be done live. Here's a sample of the script being run locally:

Detected release branch: release/frilled-dogwinkle
Got Latest PR: 734
Latest PR number from release/frilled-dogwinkle: 734

How Has This Been Tested?

Please describe the tests that you ran to verify your changes. Provide instructions so we can reproduce. Please also list any relevant details for your test configuration

• Script run locally

Checklist

• I have added tests that prove my fix is effective or that my feature works
• New and existing unit tests pass locally with my changes

Further comments

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[sonarcloud]

Quality Gate passed

Issues
0 New issues
0 Accepted issues

Measures
0 Security Hotspots
0.0% Coverage on New Code
0.0% Duplication on New Code

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