[gjs/iwyu-job: 4/8] CI: Always run IWYU with python3

[Philip Chimento <pchimento src gnome org>]

commit 664668cb867fe3ce24337038c10436d3d0027d55
Author: Philip Chimento <philip chimento gmail com>
Date:   Wed Jun 3 14:24:32 2020 -0700

    CI: Always run IWYU with python3
    
    iwyu_tool.py has /usr/bin/env python, which is not what we want on
    python3-only systems.

 tools/run_iwyu.sh | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)
---
diff --git a/tools/run_iwyu.sh b/tools/run_iwyu.sh
index 3d8cba24..f8d6a754 100755
--- a/tools/run_iwyu.sh
+++ b/tools/run_iwyu.sh
@@ -37,7 +37,7 @@ cd ${BUILDDIR:-_build}
 
 echo "files: $files"
 
-IWYU="iwyu_tool -p ."
+IWYU="python3 $(which iwyu_tool) -p ."
 PRIVATE_MAPPING="-Xiwyu --mapping_file=$SRCDIR/tools/gjs-private-iwyu.imp -Xiwyu --keep=config.h"
 PUBLIC_MAPPING="-Xiwyu --mapping_file=$SRCDIR/tools/gjs-public-iwyu.imp"
 POSTPROCESS="python3 $SRCDIR/tools/process_iwyu.py"