Use a unique name for the Go SDK that we use for ourselves

I'm not sure if this is the best way to solve this problem, but
there are two cases where we want to use this repo:

1/ We're developing the repo itself. We should be responsible for
   registering the Go toolchain.

2/ We're being used transitively by another module (eg.
   `contrib_rules_jvm`. We should _not_ be responsible for
   registering the Go toolchain

Now, in the ideal world, we'd declare the Go SDK as a dev
dependency, and everything would be fine. However, we can't do
this because there's no way to gate the call to `register_toolchain`
on us being the root module or not.

The workaround? Attempt to use a unique name for the Go SDK that
we need and hope that this works as we think it does.

gazelle/MODULE.bazel

@@ -12,13 +12,13 @@ bazel_dep(name = "rules_go", repo_name = "io_bazel_rules_go", version = "0.35.0"
 go_sdk = use_extension("@io_bazel_rules_go//go:extensions.bzl", "go_sdk")
 
 go_sdk.download(
-    name = "go_sdk",
+    name = "bazel_skylib_gazelle_plugin_go_sdk",
     version = "1.18",
 )
 
-use_repo(go_sdk, "go_sdk")
+use_repo(go_sdk, "bazel_skylib_gazelle_plugin_go_sdk")
 
-register_toolchains("@go_sdk//:all")
+register_toolchains("@bazel_skylib_gazelle_plugin_go_sdk//:all")
 
 go_deps = use_extension("@bazel_gazelle//:extensions.bzl", "go_deps")