Replace `%{output_file_path}` with `%{output_execpath}` in docs

`%{output_file_path}` is not available (anymore?).

Closes #16953.

PiperOrigin-RevId: 494059757
Change-Id: I90bd687da978a52b165334830b714a9cfc6b40a4
diff --git a/site/en/docs/cc-toolchain-config-reference.md b/site/en/docs/cc-toolchain-config-reference.md
index c49ee57..be0be10 100644
--- a/site/en/docs/cc-toolchain-config-reference.md
+++ b/site/en/docs/cc-toolchain-config-reference.md
@@ -568,7 +568,7 @@
 build command. For example:
 
     flag_group (
-        flags = ["%{output_file_path}"],
+        flags = ["%{output_execpath}"],
     )