cmd/pprof: update vendored github.com/google/pprof

cmd/pprof: update vendored github.com/google/pprof

Pull in the latest published version of github.com/google/pprof
as part of the continuous process of keeping Go's dependencies
up to date.

For #36905.

[git-generate]
cd src/cmd
go get github.com/google/pprof@v0.0.0-20251114195745-4902fdda35c8
go mod tidy
go mod vendor

Change-Id: Id26eb632f637fb2c602d87cb83fdff7f099934ce
Reviewed-on: https://go-review.googlesource.com/c/go/+/725500
Auto-Submit: Dmitri Shuralyov <dmitshur@golang.org>
LUCI-TryBot-Result: Go LUCI <golang-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: Dmitri Shuralyov <dmitshur@google.com>
Reviewed-by: Michael Pratt <mpratt@google.com>