Yarn Berry: run git lfs pull before running yarn

Dockerfile

@@ -16,6 +16,7 @@ RUN apt-get update \
     build-essential \
     dirmngr \
     git \
+    git-lfs \
     bzr \
     mercurial \
     gnupg2 \
@@ -315,3 +316,5 @@ RUN curl -sL $SHIM -o git-shim.tar.gz && mkdir -p ~/bin && tar -xvf git-shim.tar
 ENV PATH="$HOME/bin:$PATH"
 # Configure cargo to use git CLI so the above takes effect
 RUN mkdir -p ~/.cargo && printf "[net]\ngit-fetch-with-cli = true\n" >> ~/.cargo/config.toml
+# Disable automatic pulling of files stored with Git LFS
+ENV GIT_LFS_SKIP_SMUDGE=1

npm_and_yarn/lib/dependabot/npm_and_yarn/file_updater/yarn_lockfile_updater.rb

@@ -55,6 +55,8 @@ def sub_dependencies
         def updated_yarn_lock(yarn_lock)
           base_dir = dependency_files.first.directory
           SharedHelpers.in_a_temporary_repo_directory(base_dir, repo_contents_path) do
+            # Pull any yarn data or plugins which may be stored with Git LFS
+            SharedHelpers.run_shell_command("git lfs pull --include .yarn")
             write_temporary_dependency_files
             lockfile_name = Pathname.new(yarn_lock.name).basename.to_s
             path = Pathname.new(yarn_lock.name).dirname.to_s