Stop creating release PR in forked repos

[ybiquitous]

Which issue, if any, is this issue related to?

Ref: #6253

Is there anything in the PR that needs further explanation?

I notice changesets/action creates a release PR also in a forked repository, e.g., kawaguchi1102#1.

This PR adds a workaround to avoid the problem. See also changesets/action#4 (comment)

[changeset-bot]

⚠️ No Changeset found

Latest commit: 6a008ce

Merging this PR will not cause a version bump for any packages. If these changes should not result in a new version, you're good to go. If these changes should result in a version bump, you need to add a changeset.

This PR includes no changesets

When changesets are added to this PR, you'll see the packages that this PR includes changesets for and the associated semver types

Click here to learn what changesets are, and how to add one.

Click here if you're a maintainer who wants to add a changeset to this PR