checks.bash: disable go mod tidy for now

go mod tidy can make network requests.

Change-Id: I868ee60c3dc72455dcad283936c8e87c923c6e2f
Reviewed-on: https://go-review.googlesource.com/c/pkgsite-metrics/+/493055
Reviewed-by: Bryan Mills <bcmills@google.com>
Run-TryBot: Zvonimir Pavlinovic <zpavlinovic@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>
diff --git a/checks.bash b/checks.bash
index 9eed411..799517d 100755
--- a/checks.bash
+++ b/checks.bash
@@ -109,7 +109,8 @@
   check_integration
   check_headers
   go_linters
-  go_modtidy
+  # TODO(zpavlinovic): find a way to disable only for non-longtest builders.
+  #go_modtidy
 }
 
 usage() {