Use the relative path workaround in the workflow

.github/workflows/build.yml

@@ -63,13 +63,13 @@ jobs:
             install
       - name: Build the binaries
         run: |
-          # I'm not sure why, but on Ubuntu 18.04 the path to the wrap patch
-          # files is relative to the current working directory rather than the
-          # build directory
-          sed -i 's#file:\.\./subprojects#file:./subprojects#' subprojects/*.wrap
-
-          meson setup --buildtype=release --cross-file cross-wine.conf -Duse-bitbridge=true build
-          ninja -C build
+          # Ubuntu resolves the relative paths used in the meson wrap files
+          # relatively to the current working directory, so we have to setup the
+          # project directly from the build directory
+          mkdir build
+          cd build
+          meson setup --buildtype=release --cross-file ../cross-wine.conf -Duse-bitbridge=true
+          ninja
       - name: Create an archive for the binaries
         run: |
           set -e