[release-branch.go1.17] net/http: update bundled golang.org/x/net/http2

Pull in approved backports to golang.org/x/net/http2:

    85e122b net/http2: Fix handling of expect continue
    1dc0aec http2: don't count aborted streams as active in tests
    e973a42 ipv6: OpenBSD does not appear to support multicast loopback
    9592dd5 http2: avoid busy loop when ResponseHeaderTimeout is set
    94fb2bc http2: avoid spurious RoundTrip error when server closes and resets stream
    e108c19 http2: close conns after use when req.Close is set

By doing:

    $ go get -d golang.org/x/net@internal-branch.go1.17-vendor
    go: upgraded golang.org/x/net v0.0.0-20211101194204-95aca89e93de => v0.0.0-20211201233630-85e122b1a9b3
    $ go mod tidy
    $ go mod vendor
    $ go generate -run=bundle std

Fixes #49561.
Fixes #49624.
Fixes #49662.
Fixes #49905.
Fixes #49909.
Fixes #49911.

Change-Id: Ia8f432bd3ea77d24e63d46c8ed2ac8d275406b52
Reviewed-on: https://go-review.googlesource.com/c/go/+/368574


Trust: Michael Knyszek <mknyszek@google.com>
Run-TryBot: Michael Knyszek <mknyszek@google.com>
TryBot-Result: Go Bot <gobot@golang.org>
Reviewed-by: Dmitri Shuralyov <dmitshur@golang.org>