pw_presubmit: Save 'bazel info output_base'

Save the output of 'bazel info output_base' so it can be used by
infrastructure.

Change-Id: I827b80273d438f84472adcbcb231e3d07d6232de
Reviewed-on: https://pigweed-review.googlesource.com/c/pigweed/pigweed/+/206270
Reviewed-by: Taylor Cramer <cramertj@google.com>
Commit-Queue: Auto-Submit <auto-submit@pigweed-service-accounts.iam.gserviceaccount.com>
Presubmit-Verified: CQ Bot Account <pigweed-scoped@luci-project-accounts.iam.gserviceaccount.com>
Pigweed-Auto-Submit: Rob Mohr <mohrr@google.com>
diff --git a/pw_presubmit/py/pw_presubmit/build.py b/pw_presubmit/py/pw_presubmit/build.py
index a64668a..a4696d9 100644
--- a/pw_presubmit/py/pw_presubmit/build.py
+++ b/pw_presubmit/py/pw_presubmit/build.py
@@ -106,6 +106,9 @@
                     (ctx.output_dir / f'bazel.{cmd}.stdout').open('w')
                 )
 
+            with (ctx.output_dir / 'bazel.output.base').open('w') as outs:
+                call('bazel', 'info', 'output_base', tee=outs)
+
             call(
                 'bazel',
                 cmd,