[infra] Remove Win7 fyi jobs

Change-Id: I3a14d1790adecbcf742424dcf369cb1ee32d1f31
Bug: 1316545
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/535326
Reviewed-by: Brian Salomon <bsalomon@google.com>
3 files changed