fix badge

Author: peterbecich

README.md

@@ -1,6 +1,6 @@
 # hackage-server
 
-[![Build status](https://github.com/haskell/hackage-server/actions/workflows/cabal.yml/badge.svg)](https://github.com/haskell/hackage-server/actions/workflows/cabal.yml)
+[![Build status](https://github.com/haskell/hackage-server/actions/workflows/haskell-ci.yml/badge.svg)](https://github.com/haskell/hackage-server/actions/workflows/haskell-ci.yml)
 [![Build status](https://github.com/haskell/hackage-server/actions/workflows/nix-flake.yml/badge.svg)](https://github.com/haskell/hackage-server/actions/workflows/nix-flake.yml)
 
 This is the `hackage-server` code. This is what powers <http://hackage.haskell.org>, and many other private hackage instances. The `master` branch is suitable for general usage. Specific policy and documentation for the central hackage instance exists in the `central-server` branch.