Add `exec_compatible_with = HOST_CONSTRAINTS` to rules (#113)

This ensures they work out-of-the-box in a multi-platform build when the
highest priority platform isn’t the host platform.

---------

Signed-off-by: Brentley Jones <github@brentleyjones.com>

MODULE.bazel

diff --git a/MODULE.bazel b/MODULE.bazel
index f5ed3c3..29924b8 100644
--- a/MODULE.bazel
+++ b/MODULE.bazel
@@ -5,7 +5,7 @@
 )
 
 bazel_dep(name = "bazel_skylib", version = "1.3.0")
-bazel_dep(name = "platforms", version = "0.0.5")
+bazel_dep(name = "platforms", version = "0.0.11")
 
 buildifier_prebuilt = use_extension("//:defs.bzl", "buildifier_prebuilt_deps_extension")
 buildifier_prebuilt.toolchains()

rules.bzl

diff --git a/rules.bzl b/rules.bzl
index 3998578..a9650b1 100644
--- a/rules.bzl
+++ b/rules.bzl
@@ -2,6 +2,7 @@
 Rules to use the prebuilt buildifier / buildozer binaries
 """
 
+load("@local_config_platform//:constraints.bzl", "HOST_CONSTRAINTS")
 load("//buildifier:buildifier_binary.bzl", _buildifier_binary = "buildifier_binary")
 load(
     "//buildifier:factory.bzl",
@@ -19,6 +20,7 @@
 buildifier = rule(
     implementation = _buildifier_impl,
     attrs = buildifier_attr_factory(test_rule = False),
+    exec_compatible_with = HOST_CONSTRAINTS,
     toolchains = ["@buildifier_prebuilt//buildifier:toolchain"],
     executable = True,
 )
@@ -29,6 +31,7 @@
 _buildifier_test = rule(
     implementation = _buildifier_test_impl,
     attrs = buildifier_attr_factory(test_rule = True),
+    exec_compatible_with = HOST_CONSTRAINTS,
     toolchains = ["@buildifier_prebuilt//buildifier:toolchain"],
     test = True,
 )