Update image used to build

Author: bording

.github/workflows/ci.yml

@@ -55,7 +55,7 @@ jobs:
         run: ./build.libgit2.sh
       - name: Setup QEMU
         run: docker run --rm --privileged multiarch/qemu-user-static:register --reset
-        if: matrix.name == 'linux-musl-arm' || matrix.name == 'linux-musl-arm64'
+        if: matrix.name == 'linux-arm' || matrix.name == 'linux-arm64' || matrix.name == 'linux-musl-arm' || matrix.name == 'linux-musl-arm64'
       - name: Build Linux
         if: runner.os == 'Linux'
         run: ./dockerbuild.sh

Dockerfile.linux

@@ -1,6 +1,5 @@
-FROM multiarch/crossbuild
 ARG ARCH='amd64'
-ENV CROSS_TRIPLE=${ARCH}
+FROM multiarch/ubuntu-core:${ARCH}-focal
 RUN apt update && apt -y install pkg-config
 
 WORKDIR /nativebinaries