cmd: update x/term to pull in CL 316112

Even though x/term is now lazy, this has no overall effect (yet) on
the contents of cmd/go.sum, because the dependency that would be
pruned out (an old version of x/sys) is still transitively required
through x/crypto, x/sys, and/or x/tools.

Once those modules are also lazy (CL 316109, CL 316111, and CL 315570
respectively), the extra go.sum entries for x/sys will drop out.

For #36460
Updates #36905

Change-Id: I79e715328f7c417ea20ae8fe4f8e0e3eb71ee6c7
Reviewed-on: https://go-review.googlesource.com/c/go/+/316250


Trust: Bryan C. Mills <bcmills@google.com>
Run-TryBot: Bryan C. Mills <bcmills@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>