[build] Disable output leak scanning on verification tools

These tools don't have output files with contents, so don't pay
the tax of running them with the output leak verification script.

Change-Id: I1e112f71dea925c0d77e636b6d458b805426e6ef
Reviewed-on: https://fuchsia-review.googlesource.com/c/fuchsia/+/1338128
Reviewed-by: David Fang <[email protected]>
Commit-Queue: Aaron Wood <[email protected]>
Fuchsia-Auto-Submit: Aaron Wood <[email protected]>

Author: woody77

tools/cmc/build/expect_includes.gni

@@ -151,6 +151,10 @@ template("cmc_check_includes") {
     outputs = [ "$target_out_dir/$target_name.gn_stamp" ]
     depfile = "$target_gen_dir/$target_name.d"
 
+    # As this action only writes an empty stamp file, there's no need to run
+    # the check for any output dir leaks in the file.
+    check_for_output_dir_leaks = false
+
     args = [
              "--cmc-path",
              rebase_path(cmc_out_path, root_build_dir),

tools/configc/build/config.gni

@@ -398,6 +398,10 @@ template("validate_packaged_config") {
     ]
     outputs = [ _stamp ]
 
+    # As this action only writes a stamp file, there's no need to run
+    # the check for any output dir leaks in the file.
+    check_for_output_dir_leaks = false
+
     if (!defined(deps)) {
       deps = []
     }