net: TestFileListener/unixpacket failures

[gopherbot]

#!watchflakes
default <- pkg == "net" && test == "TestFileListener/unixpacket"

Issue created automatically to collect these failures.

Example (log):

=== RUN   TestFileListener/unixpacket
    file_test.go:197: dial unixpacket /home/swarming/.swarming/w/ir/x/t/3802835418/sock: connect: connection refused
--- FAIL: TestFileListener/unixpacket (0.02s)

— watchflakes

[gopherbot]

Found new dashboard test flakes for:

#!watchflakes
default <- pkg == "net" && test == "TestFileListener/unixpacket"

2026-07-30 20:19 gotip-openbsd-amd64 go@7cc6ec23 net.TestFileListener/unixpacket (log)

=== RUN   TestFileListener/unixpacket
    file_test.go:197: dial unixpacket /home/swarming/.swarming/w/ir/x/t/3802835418/sock: connect: connection refused
--- FAIL: TestFileListener/unixpacket (0.02s)

— watchflakes

[cagedmantis]

cc @ianlancetaylor @neild @nicholashusin