Make the publish NuGet action use a manual trigger with validation

[joelhulen]

Make the publish NuGet action use a manual trigger with validation

The issue or feature being addressed

Changes the action to run manually instead of automatically.

Details on the issue fix or feature implementation

This GitHub Action builds and publishes NuGet packages when pushing to release branches. This PR changes the action to be triggered manually instead of automatically, but it still restricts running the action only on release branches. The reason for this is that NuGet packages are immutable. Once published, you cannot update them, which makes them problematic when making subsequent updates to a release branch.

Confirm the following

• I started this PR by branching from the head of the default branch
• I have targeted the PR to merge into the default branch
• This PR needs to be cherry-picked into at least one release branch
• I have included unit tests for the issue/feature
• I have included inline docs for my changes, where applicable
• I have successfully run a local build
• I have provided the required update scripts, where applicable
• I have updated relevant docs, where applicable

Note

Instead of adding X's inside the checkboxes you wish to check above, first submit the PR, then check the boxes in the rendered description.