cmd/bent: rename benchmarks-50.toml to benchmarks-100.toml

And now it runs 98 benchmarks.
(Two from k8s/-cache were just removed because they leak goroutines).

These are semi-curated; further review might be useful for
determining which ones are just memmove benchmarks.

This might fix the automated benchmark runner, might not.

Updates #80564.

Change-Id: I03f6a2f7976072dde55a5d7e812d3345b6aec5a3
Reviewed-on: https://go-review.googlesource.com/c/benchmarks/+/807020
Reviewed-by: Carlos Amedee <carlos@golang.org>
LUCI-TryBot-Result: golang-scoped@luci-project-accounts.iam.gserviceaccount.com <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Junyang Shao <shaojunyang@google.com>
Reviewed-by: Cherry Mui <cherryyz@google.com>