Remove obsolete Bazel spawn strategies

After the latest Bazel upgrade, the --spawn_strategy=standalone
doesn't show the output of the subprocess created, making the
troubleshoot of the failures impossible.

Change-Id: I8308d347739cb06469395b8cf3bce5f982ccc32b
1 file changed
tree: 0b26fe3e37f449e7674ae832bdea63f958766a58
  1. .gitreview
  2. LICENSE
  3. README
  4. playbooks/
  5. roles/
  6. zuul.d/