[bazel] Migrate nonhermetic repo to bzlmod

Signed-off-by: James Wainwright <[email protected]>

Author: jwnrt

MODULE.bazel

@@ -40,6 +40,10 @@ bitstreams_repo = use_repo_rule("//rules:bitstreams.bzl", "bitstreams_repo")
 
 bitstreams_repo(name = "bitstreams")
 
+nonhermetic_repo = use_repo_rule("//rules:nonhermetic.bzl", "nonhermetic_repo")
+
+nonhermetic_repo(name = "nonhermetic")
+
 # Source repositories (not Bazel-aware):
 github_tools = use_extension("//third_party/github:extensions.bzl", "github_tools")
 use_repo(github_tools, "com_github_gh")

WORKSPACE.bzlmod

@@ -18,10 +18,6 @@ crt_deps()
 load("@crt//config:registration.bzl", "crt_register_toolchains")
 crt_register_toolchains(riscv32 = True)
 
-# The nonhermetic_repo imports environment variables needed to run vivado.
-load("//rules:nonhermetic.bzl", "nonhermetic_repo")
-nonhermetic_repo(name = "nonhermetic")
-
 register_toolchains(
     "//rules/opentitan:localtools",
 )