Target a space when running `pcf target` in CI.
Target a space when running `pcf target` in CI.

We've had some jobs hang waiting to choose a space,e.g.,
https://concourse.cfplatformeng.com/teams/main/pipelines/tile-generator/jobs/deploy-tile-2_3/builds/7

cf-platform-eng/tile-generator,cf-platform-eng/tile-generator,cf-platform-eng/tile-generator,cf-platform-eng/tile-generator