net/http: test flake in TestTransportIgnores408/h1

[ianlancetaylor]

Seen on a trybot. Did not find an existing issue. CC @neild @bradfitz

https://storage.googleapis.com/go-build-log/4868bfba/linux-amd64_7494de7d.log

--- FAIL: TestTransportIgnores408 (0.00s)
    --- FAIL: TestTransportIgnores408/h1 (0.01s)
        transport_test.go:6017: expected no log output; got: 2022/10/09 03:30:01 http: TLS handshake error from 127.0.0.1:51852: EOF
            2022/10/09 03:30:01 http: TLS handshake error from 127.0.0.1:35068: EOF
2022/10/09 03:30:01 http: TLS handshake error from 127.0.0.1:46010: read tcp 127.0.0.1:45467->127.0.0.1:46010: use of closed network connection
2022/10/09 03:30:01 http: TLS handshake error from 127.0.0.1:45980: read tcp 127.0.0.1:45467->127.0.0.1:45980: use of closed network connection
2022/10/09 03:30:01 http: TLS handshake error from 127.0.0.1:46022: write tcp 127.0.0.1:45467->127.0.0.1:46022: use of closed network connection
2022/10/09 03:30:01 http: TLS handshake error from 127.0.0.1:45996: read tcp 127.0.0.1:45467->127.0.0.1:45996: use of closed network connection
2022/10/09 03:30:01 http: TLS handshake error from 127.0.0.1:46036: write tcp 127.0.0.1:45467->127.0.0.1:46036: use of closed network connection
2022/10/09 03:30:01 http: TLS handshake error from 127.0.0.1:46046: write tcp 127.0.0.1:45467->127.0.0.1:46046: use of closed network connection
2022/10/09 03:30:01 http: TLS handshake error from 127.0.0.1:54726: read tcp 127.0.0.1:44951->127.0.0.1:54726: use of closed network connection
2022/10/09 03:30:01 http: TLS handshake error from 127.0.0.1:54764: write tcp 127.0.0.1:44951->127.0.0.1:54764: use of closed network connection
2022/10/09 03:30:01 http: TLS handshake error from 127.0.0.1:54716: write tcp 127.0.0.1:44951->127.0.0.1:54716: use of closed network connection
2022/10/09 03:30:01 http: TLS handshake error from 127.0.0.1:54780: write tcp 127.0.0.1:44951->127.0.0.1:54780: use of closed network connection
2022/10/09 03:30:01 http: TLS handshake error from 127.0.0.1:54740: write tcp 127.0.0.1:44951->127.0.0.1:54740: use of closed network connection
2022/10/09 03:30:01 http: TLS handshake error from 127.0.0.1:54790: write tcp 127.0.0.1:44951->127.0.0.1:54790: use of closed network connection
2022/10/09 03:30:01 http: TLS handshake error from 127.0.0.1:54752: write tcp 127.0.0.1:44951->127.0.0.1:54752: use of closed network connection
2022/10/09 03:30:01 http2: server: error reading preface from client 127.0.0.1:60128: bogus greeting "CONNECT golang.fake.tld:"
2022/10/09 03:30:01 http2: server: error reading preface from client 127.0.0.1:37392: bogus greeting "CONNECT golang.fake.tld:"
FAIL
FAIL	net/http	2.757s
FAIL

[4a6f656c]

I suspect this may be fixed via https://go-review.googlesource.com/c/go/+/442495

[neild]

Should be fixed by that CL, yes.