Make buildifier a dev dependency (#228)

This seems to be a clear dev dependency that should not be exposed to
the user

MODULE.bazel

diff --git a/MODULE.bazel b/MODULE.bazel
index fe63790..08c560e 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -7,11 +7,12 @@
 )
 
 bazel_dep(name = "bazel_skylib", version = "1.4.1")
-bazel_dep(name = "buildifier_prebuilt", version = "7.3.1")
 bazel_dep(name = "platforms", version = "0.0.8")
 bazel_dep(name = "rules_multitool", version = "0.11.0")
 bazel_dep(name = "rules_python", version = "0.34.0")
 
+bazel_dep(name = "buildifier_prebuilt", version = "7.3.1", dev_dependency = True)
+
 multitool = use_extension("@rules_multitool//multitool:extension.bzl", "multitool")
 multitool.hub(lockfile = "//uv/private:uv.lock.json")
 use_repo(multitool, "multitool")