Make powershell.exe available at build time

After flipping --experimental_strict_action_env, we need to pass --action_env=PATH to make sure some specific tools are available on Windows.
Fixing https://buildkite.com/bazel/bazel-at-head-plus-disabled/builds/4#a868eb9b-dc52-4ce1-8adb-0da82e8a407b

PiperOrigin-RevId: 226040594
diff --git a/.bazelci/presubmit.yml b/.bazelci/presubmit.yml
index 855be68..86b7f3b 100644
--- a/.bazelci/presubmit.yml
+++ b/.bazelci/presubmit.yml
@@ -40,8 +40,12 @@
     run_targets:
     - "//:gazelle"
     - "@nodejs//:yarn"
+    build_flags:
+    - "--action_env=PATH"
     build_targets:
     - "..."
     - "@disable_tsetse_for_external_test//..."
+    test_flags:
+    - "--test_env=PATH"
     test_targets:
     - "..."