Bazel: move patching of rules_kotlin to a registry override

java/kotlin-extractor/rules_kotlin.patch

@@ -1,32 +0,0 @@
-diff --git a/src/main/starlark/core/options/opts.kotlinc.bzl b/src/main/starlark/core/options/opts.kotlinc.bzl
-index 9b15fb8..c0ac2cd 100644
---- a/src/main/starlark/core/options/opts.kotlinc.bzl
-+++ b/src/main/starlark/core/options/opts.kotlinc.bzl
-@@ -28,6 +28,11 @@ def _map_jvm_target_to_flag(version):
-         return None
-     return ["-jvm-target=%s" % version]
- 
-+def _map_language_version_to_flag(version):
-+    if not version:
-+        return None
-+    return ["-language-version=%s" % version, "-api-version=%s" % version]
-+
- _KOPTS_ALL = {
-     "warn": struct(
-         args = dict(
-@@ -349,6 +354,15 @@ _KOPTS_ALL = {
-         value_to_flag = None,
-         map_value_to_flag = _map_jvm_target_to_flag,
-     ),
-+    "language_version": struct(
-+        args = dict(
-+            default = "1.9",
-+            doc = "-language-version",
-+        ),
-+        type = attr.string,
-+        value_to_flag = None,
-+        map_value_to_flag = _map_language_version_to_flag,
-+    ),
- }
- 
- # Filters out options that are not available in current compiler release