docs: Discourage use go_sdk.host() in bzlmod.md (see #3967) (#3968)

see #3967

and enola-dev/enola#713

docs/go/core/bzlmod.md

@@ -44,6 +44,10 @@ go_sdk.download(
 go_sdk.host()
 ```
 
+Nota bene: The use of `go_sdk.host()` [may break builds](https://github.com/enola-dev/enola/issues/713) whenever the host Go version is upgraded
+(because many OS package managers, such as Debian/Ubuntu's `apt`, distribute Go into a directory which contains the version, such as `/usr/lib/go-1.22/`).
+As package upgrades happen outside of Bazel's control, this will lead to non-reproducible builds. Due to this, use of `go_sdk.host()` is discouraged.
+
 You can register multiple Go SDKs and select which one to use on a per-target basis using [`go_cross_binary`](rules.md#go_cross_binary).
 As long as you specify the `version` of an SDK, it will be downloaded lazily, that is, only when it is actually needed during a particular build.
 The usual rules of [toolchain resolution](https://bazel.build/extending/toolchains#toolchain-resolution) apply, with SDKs registered in the root module taking precedence over those registered in dependencies.