build: update `yarn.lock` (#3489)
build: update `yarn.lock` (#3489)

Summary:
Bazel keeps trying to regenerate this, adding ~25 seconds of latency to
seemingly random `bazel` commands. Hopefully this will fix it.

Generated by checking out a clean copy of origin/master and running
`bazel query //tensorboard`, which has the side effect of updating
`yarn.lock`.

Test Plan:
Ran `bazel query //tensorboard` again, and… it regenerated it, not
making any changes. But I ran it a third time and it did nothing. Only
time will tell.

wchargin-branch: regenerate-yarn-lock-20200406
tensorflow/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard,tensorflow/tensorboard