Enable LFS automatic pulling for the go_modules ecosystem

Turning GIT_LFS_SKIP_SMUDGE on enables automatic pulling by default.
This default is respected by the Go toolchain when downloading module
sources directly from git servers (e.g. GitHub).

Git LFS support is important when Go modules embed large files using
go:embed. Direct download is more common for private repositories but
it is also possible for public repositories (which are often downloaded
from the module-proxy).

The Go toolchain uses the local git installation to fetch archives of
modules from Git servers directly. Some companies commits large files
using Git LFS which happen to be part of their Go module source tree.
Without git-lfs installed, the local git installation does not
automatically resolve those files which causes "checksum mismatch"
against the committed go.sum.

go_modules/Dockerfile

@@ -27,3 +27,10 @@ ENV GOTOOLCHAIN="go1.20.10"
 # This pre-installs go 1.20 so that each job doesn't have to do it.
 RUN go version
 ENV GO_LEGACY=$GOTOOLCHAIN
+
+# Enable automatic pulling of files stored with Git LFS.
+# This is crucial for the Go toolchain to correctly compute module hashes in repositories
+# with LFS committed files.
+# This is relevant only for Go Modules embedding (with //go:embed) large files and does not
+# affect repositories that do not commit files to LFS.
+ENV GIT_LFS_SKIP_SMUDGE=1