Improve likelihood of Cherry Picking script including all PRs

[getdave]

What?

Improves the liklihood that the Cherry Picking script will fetch all the PRs that need to be cherry picked.

Closes #59210

Why?

The Github API paginates it's results with a default of 30. It is possible that for a given release there will be more than 30 PRs that need to be picked into the relevant release branch.

This needs fixing so that future release leads don't end up missing PRs. I already updated the release docs with this extra warning but it makes sense to also improve the tooling.

How?

Adds the per_page param to the request and sets it to 100.

I see this as a "good enough" fix. If there are more than 100 PRs in a given release we have a bigger problem 😆

Testing Instructions

• We can run the script passing a label we know will have a lot of PRs. This is to simulate testing for a release where lots of PRs are labeled with the default label.
• Do not propagate the results to Github - you can say "no" when prompted to avoid this.
• Run npm run other:cherry-pick -- "[Type] Bug".
• Check that more than 30 PRs are found.

Testing Instructions for Keyboard

Screenshots or screencast

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[youknowriad]

That makes sense to me. Thanks.