pw_toolchain: Cleanup transition flag

Removes temporary flag required for updating rules_cc.

Fixes: b/384050813
Change-Id: Ib3d3b41ed10be253acd8bde24a6ae8b2976ca9d0
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/254433
Lint: Lint 🤖 <[email protected]>
Pigweed-Auto-Submit: Armando Montanez <[email protected]>
Reviewed-by: Ted Pudlik <[email protected]>
Presubmit-Verified: CQ Bot Account <[email protected]>
Docs-Not-Needed: Armando Montanez <[email protected]>
Commit-Queue: Auto-Submit <[email protected]>

pw_toolchain/host_clang/BUILD.bazel

@@ -248,38 +248,8 @@ cc_args(
 )
 
 cc_feature(
-    name = "supports_pic_old",
-    overrides = "@rules_cc//cc/toolchains/features:supports_pic",
-    tags = ["manual"],
-    visibility = ["//visibility:private"],
-)
-
-# TODO: https://pwbug.dev/384050813 - This flag is a temporary transition flag
-# that will be removed shortly.
-bool_flag(
-    name = "new_rules_cc",
-    build_setting_default = True,
-)
-
-config_setting(
-    name = "rules_cc_post_0.0.10",
-    flag_values = {
-        ":new_rules_cc": "True",
-    },
-)
-
-cc_feature(
-    name = "supports_pic_actual",
-    feature_name = "supports_pic",
-    visibility = ["//visibility:private"],
-)
-
-alias(
     name = "supports_pic",
-    actual = select({
-        ":rules_cc_post_0.0.10": "supports_pic_actual",
-        "//conditions:default": "supports_pic_old",
-    }),
+    feature_name = "supports_pic",
 )
 
 # Symlink to clangd, for user convenience.