Update Buildkite badge URL to include branch (#550)

Author: michel2323

README.md

@@ -7,7 +7,7 @@
 [doi-img]: https://zenodo.org/badge/252466420.svg
 [doi-url]: https://zenodo.org/badge/latestdoi/252466420
 
-[buildkite-img]: https://badge.buildkite.com/00fff01fd4d6cdd905e61e2ce7ed0f7203ba227df9b575426c.svg
+[buildkite-img]: https://badge.buildkite.com/00fff01fd4d6cdd905e61e2ce7ed0f7203ba227df9b575426c.svg?branch=master
 [buildkite-url]: https://buildkite.com/julialang/oneapi-dot-jl
 
 [codecov-img]: https://codecov.io/gh/JuliaGPU/oneAPI.jl/branch/master/graph/badge.svg