Deduplicate calls to config.is_sibling_repository_layout()

This showed up in Starlark CPU profiles and is not negligible as it repeatedly checks allowlists.

Closes bazelbuild#23256.

PiperOrigin-RevId: 671444687
Change-Id: I6e64b0c94332a54fcc5d531ff0e3aab176b7bd0a

Author: fmeum

src/main/starlark/builtins_bzl/common/cc/cc_compilation_helper.bzl

@@ -348,15 +348,15 @@ def _init_cc_compilation_context(
             pic_header_module = _header_module_artifact(
                 actions,
                 label,
-                config.is_sibling_repository_layout(),
+                sibling_repo_layout,
                 "",
                 ".pic.pcm",
             )
         if generates_no_pic_header_module:
             header_module = _header_module_artifact(
                 actions,
                 label,
-                config.is_sibling_repository_layout(),
+                sibling_repo_layout,
                 "",
                 ".pcm",
             )
@@ -366,15 +366,15 @@ def _init_cc_compilation_context(
                 separate_module = _header_module_artifact(
                     actions,
                     label,
-                    config.is_sibling_repository_layout(),
+                    sibling_repo_layout,
                     ".sep",
                     ".pcm",
                 )
             if generates_pic_header_module:
                 separate_pic_module = _header_module_artifact(
                     actions,
                     label,
-                    config.is_sibling_repository_layout(),
+                    sibling_repo_layout,
                     ".sep",
                     ".pic.pcm",
                 )