clean up SK_SUPPORT_LEGACY_RUNTIME_EFFECTS

Cq-Include-Trybots: luci.chromium.try:linux-blink-rel
Change-Id: I4475982f0a5b17bcc4bae4b3f75557969cc70fd2
Reviewed-on: https://skia-review.googlesource.com/c/skia/+/369856
Reviewed-by: Mike Reed <reed@google.com>
Commit-Queue: Mike Klein <mtklein@google.com>
14 files changed