Auto merge of #8011 - ehuss:pr-ci, r=alexcrichton
Auto merge of #8011 - ehuss:pr-ci, r=alexcrichton

Run CI on all PRs.

I think we want PRs to be tested on all branches (such as beta branches). This is the default for Azure, so there's no need to specify the PR trigger.

vojtechkral/cargo,tsurai/cargo,vojtechkral/cargo,tshepang/cargo,tsurai/cargo,rust-lang/cargo,eminence/cargo,nipunn1313/cargo,tshepang/cargo,tshepang/cargo,tsurai/cargo,rust-lang/cargo,vojtechkral/cargo,vojtechkral/cargo,rustyhorde/cargo,rust-lang/cargo,rustyhorde/cargo,rustyhorde/cargo,nipunn1313/cargo,nipunn1313/cargo,rustyhorde/cargo,tsurai/cargo,eminence/cargo,tshepang/cargo,nipunn1313/cargo,eminence/cargo,tsurai/cargo,eminence/cargo,rust-lang/cargo