Made cron actions to only run on upstream

[ariel-anieli]

Proposed Changes

• cron actions keep failing on my local repo
• from the GitHub debug, it seems they are missing tokens passed as secrets.

# git grep 'cron:'
.github/workflows/check-build-system-equivalence-release-branches.yaml:  - cron: '0 2 * * *'
.github/workflows/gazelle-scheduled.yaml:  - cron: '0 4 * * *'
.github/workflows/test-windows.yaml:  - cron: '0 2 * * *'

# bazel run gazelle (main)
Input 'token' not supplied. Unable to continue.

# check-v3_13_x / bazel build package-generic-unix.tar.xz
couldn't find remote ref refs/heads/v3.13.x

Types of Changes

What types of changes does your code introduce to this project? Put an x in the boxes that apply

• [ ] Bug fix (non-breaking change which fixes issue #NNNN)
• [ ] New feature (non-breaking change which adds functionality)
• [ ] Breaking change (fix or feature that would cause an observable behavior change in existing systems)
• [ ] Documentation improvements (corrections, new content, etc)
• [ ] Cosmetic change (whitespace, formatting, etc)
• [x] Build system and/or CI

Checklist

• [x] I have read the CONTRIBUTING.md document
• [x] I have signed the CA (see https://cla.pivotal.io/sign/rabbitmq)
• [ ] I have added tests that prove my fix is effective or that my feature works
• [ ] All tests pass locally with my changes
• [ ] If relevant, I have added necessary documentation to https://github.com/rabbitmq/rabbitmq-website
• [ ] If relevant, I have added this change to the first version(s) in release-notes that I expect to introduce it

Further Comments

I am looking forward your feedback.