Ensure the stale workflow uses fewer operations

[epk]

We only get 1,000 operations per hour for every workflow that uses GITHUB_TOKEN. We're now seeing the stale workflow use relatively few operations with few to no stale issues open.

In addition to lowering the workflow's operation limit this change has the workflow run once a day. It adds a new /fresh comment command that can be used to instantly mark an issue or PR as not stale, rather than waiting up to a day for the stale workflow to run.

Signed-off-by: Aditya Sharma git@adi.run

Description of your changes

Similar to https://github.com/crossplane/crossplane/pull/3258

I have:

• [x] Read and followed Crossplane's contribution process.
• [x] Run make reviewable test to ensure this PR is ready for review.

How has this code been tested

[negz]

Thanks @epk! Would you mind updating the PR description? I'm guessing this is what the commits you copied over from c/c say, but in this case we're adding net new actions and I'd like the PR description to reflect that.

[negz]

FYI it looks like /fresh is broken per https://github.com/crossplane/crossplane/pull/3276