Auto merge of rust-lang#5163 - flip1995:gha_fix, r=flip1995

Change badge branch from master to auto

For some reason GHA classifies the bors merges on the master branch as a
push to the auto branch, even though the workflow got triggered by a
push to the master branch. I guess this has something to do with the
same commit hash on master+auto directly after the merge?

changelog: none

Author: bors

README.md

@@ -2,7 +2,7 @@
 
 [![Build Status](https://travis-ci.com/rust-lang/rust-clippy.svg?branch=master)](https://travis-ci.com/rust-lang/rust-clippy)
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+[![Clippy Test](https://github.com/rust-lang/rust-clippy/workflows/Clippy%20Test/badge.svg?branch=auto&event=push)](https://github.com/rust-lang/rust-clippy/actions?query=workflow%3A%22Clippy+Test%22+event%3Apush+branch%3Aauto)
 [![License: MIT OR Apache-2.0](https://img.shields.io/crates/l/clippy.svg)](#license)
 
 A collection of lints to catch common mistakes and improve your [Rust](https://github.com/rust-lang/rust) code.