The symbol_history table is no longer being used and is dropped.
Change-Id: Ib7b399869b7e46d37a727a3cea1c631ca218ab1f
Reviewed-on: https://go-review.googlesource.com/c/pkgsite/+/304750
Trust: Julie Qiu <julie@golang.org>
Run-TryBot: Julie Qiu <julie@golang.org>
TryBot-Result: kokoro <noreply+kokoro@google.com>
Reviewed-by: Jonathan Amsterdam <jba@google.com>
Julie Qiu