database/sql: use t.Context in tests
Replace "context.WithCancel(context.Background())" with "t.Context()".
Updates #36532
Change-Id: I78a8ba422f076f4c697910922cf6dc35c628b1a7
GitHub-Last-Rev:
2eacdbe9ea97ac8d928704c2b605b276626d95dd
GitHub-Pull-Request: golang/go#71599
Reviewed-on: https://go-review.googlesource.com/c/go/+/647555
Reviewed-by: Jorropo <jorropo.pgm@gmail.com>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Auto-Submit: Ian Lance Taylor <iant@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>