Use images from Quay (#2620)

I now mirror the *GHC musl* images to both Docker Hub and Quay:

* https://hub.docker.com/r/benz0li/ghc-musl
* https://quay.io/repository/benz0li/ghc-musl

Docker Hub imposes a rate limit. Quay, on the other hand, does not.

This also ensures the long-term availability of these images.

.github/workflows/linux-static-binary.yaml

@@ -15,7 +15,7 @@ jobs:
   build:
     name: Build static binary
     runs-on: ubuntu-latest
-    container: glcr.b-data.ch/ghc/ghc-musl:9.4.5
+    container: quay.io/benz0li/ghc-musl:9.4.5
     steps:
       - name: checkout code
         uses: actions/checkout@v3