Add .info file to list of repack template outputs

In addition to .pak files, //tools/grit/pak_util.py outputs .info files.
This however is not reflected in the gn template list of outputs. This
can cause errors with running ninja with '-d explain' after a successful
build which the trybots do.

Bug: 1045024
Change-Id: Id4e8915cff182f5d7c55cb947f4f2aa513ccc2b4
Reviewed-on: https://chromium-review.googlesource.com/c/chromium/src/+/2031530
Auto-Submit: Mohamed Heikal <mheikal@chromium.org>
Reviewed-by: Andrew Grieve <agrieve@chromium.org>
Commit-Queue: Andrew Grieve <agrieve@chromium.org>
Cr-Commit-Position: refs/heads/master@{#737017}

tools/grit/repack.gni

@@ -54,7 +54,10 @@ template("repack") {
     script = "//tools/grit/pak_util.py"
 
     inputs = invoker.sources
-    outputs = [ invoker.output ]
+    outputs = [
+      invoker.output,
+      "${invoker.output}.info",
+    ]
 
     args = [ "repack" ]
     if (defined(invoker.repack_whitelist)) {