net/http: TestHeadResponses failures

[gopherbot]

#!watchflakes
post <- pkg == "net/http" && test == "TestHeadResponses"

Issue created automatically to collect these failures.

Example (log):

--- FAIL: TestHeadResponses (0.00s)
    --- FAIL: TestHeadResponses/h1 (0.03s)
        testing.go:1446: race detected during execution of test
    --- FAIL: TestHeadResponses/h2 (0.04s)
        testing.go:1446: race detected during execution of test

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
post <- pkg == "net/http" && test == "TestHeadResponses"

2023-02-01 19:47 linux-amd64-race go@ab0f0459 net/http.TestHeadResponses (log)

--- FAIL: TestHeadResponses (0.00s)
    --- FAIL: TestHeadResponses/h1 (0.03s)
        testing.go:1446: race detected during execution of test
    --- FAIL: TestHeadResponses/h2 (0.04s)
        testing.go:1446: race detected during execution of test

2023-02-01 21:30 darwin-amd64-race go@4b7f7eef net/http.TestHeadResponses (log)

--- FAIL: TestHeadResponses (0.00s)

— watchflakes

[bcmills]

Duplicate of #58168