fix: Danger - recognize PR links based on full URL instead of just the PR number.

[vaind]

This was an issue with there was another link in the changelog that had the same number as the current PR.

Reported by @romtsn on Discord

e.g. I've opened a new PR with id 643 https://github.com/getsentry/sentry-android-gradle-plugin/blob/fed6ae5645b62abbeea32354b74d623e01b7294c/CHANGELOG.md?plain=1#L10, but there's already an entry #643 which references the sentry-java repo and hence it fails https://github.com/getsentry/sentry-android-gradle-plugin/blob/fed6ae5645b62abbeea32354b74d623e01b7294c/CHANGELOG.md?plain=1#L447

[romtsn]

great, thanks! I'm not sure if we use this action in the repos where we do not include the PR link into the changelog entry (like sentry-javascript), but for us it works!

[romtsn]

yeah, won't work for sentry-wizard for example https://github.com/getsentry/sentry-wizard/blob/master/CHANGELOG.md

[vaind]

yeah, won't work for sentry-wizard for example getsentry/sentry-wizard@master/CHANGELOG.md

thanks for pointing that out, I'll make it work in both cases