ci: binaries-linux-x64: try a fix for unwritable $HOME issue

work around actions/runner#863 which is causing
"Preventing creation of Stack root '/github/home/.stack/'. Parent directory '/github/home/' is owned by someone else."

.github/workflows/binaries-linux-x64.yml

@@ -122,6 +122,13 @@ jobs:
       run: |
         apk --no-cache add binutils-gold curl gcc g++ git gmp-dev ncurses-dev ncurses-static libffi-dev make xz tar perl zlib-dev zlib-static
 
+    - name: Fix $HOME for following steps (work around https://github.com/actions/runner/issues/863)
+      run: |
+        ls /
+        ls /home
+        whoami
+        sudo sh -c "echo HOME=/home/github >> $GITHUB_ENV"
+
     - name: Add .ghcup/bin to PATH for following steps
       run: |
         echo "$HOME/.ghcup/bin/" >> $GITHUB_PATH