net/http2: `timeout waiting for Write in handler` in TestServer_Response_RST_Unblocks_LargeWrite

[bcmills]

--- FAIL: TestServer_Response_RST_Unblocks_LargeWrite (2.34s)
    server_test.go:2680: Error in handler: timeout waiting for Write in handler
    server_test.go:261: Framer read log:
        2022-05-28 12:35:04.365715655 Framer 0x400056c0e0: read SETTINGS len=24, settings: MAX_FRAME_SIZE=1048576, MAX_CONCURRENT_STREAMS=250, MAX_HEADER_LIST_SIZE=1048896, INITIAL_WINDOW_SIZE=1048576
        2022-05-28 12:35:04.365982786 Framer 0x400056c0e0: read WINDOW_UPDATE len=4 (conn) incr=983041
        2022-05-28 12:35:04.367350193 Framer 0x400056c0e0: read SETTINGS flags=ACK len=0
        2022-05-28 12:35:04.371225909 Framer 0x400056c0e0: read SETTINGS flags=ACK len=0
        2022-05-28 12:35:06.624451923 Framer 0x400056c0e0: read HEADERS flags=END_HEADERS stream=1 len=25
    server_test.go:267: Framer write log:
        2022-05-28 12:35:04.362434078 Framer 0x400056c0e0: wrote SETTINGS len=0
        2022-05-28 12:35:04.365793032 Framer 0x400056c0e0: wrote SETTINGS flags=ACK len=0
        2022-05-28 12:35:04.367451862 Framer 0x400056c0e0: wrote SETTINGS len=12, settings: INITIAL_WINDOW_SIZE=0, MAX_FRAME_SIZE=16384
        2022-05-28 12:35:04.371392121 Framer 0x400056c0e0: wrote HEADERS flags=END_STREAM|END_HEADERS stream=1 len=16
        2022-05-28 12:35:06.624552592 Framer 0x400056c0e0: wrote RST_STREAM stream=1 len=4 ErrCode=CANCEL
FAIL
FAIL	golang.org/x/net/http2	79.864s

greplogs -l -e 'timeout waiting for Write in handler'
2022-05-27T14:59:03-5463443-03c2e56/netbsd-arm64-bsiegert

[bcmills]

The hard-coded timeouts in testServerResponse look problematic to me, independent of platform:
https://cs.opensource.google/go/x/net/+/master:http2/server_test.go;l=2673;drc=183a9ca12b87817e0ced91cdd139606cbb193ef2
https://cs.opensource.google/go/x/net/+/master:http2/server_test.go;l=2682;drc=183a9ca12b87817e0ced91cdd139606cbb193ef2

[gopherbot]

Change https://go.dev/cl/409574 mentions this issue: http2: eliminate arbitrary timeouts in testServerResponse