fix: git daemon listens only when starting it

[jaw]

This was inconsistent with the other servers.

[aymanbagabas]

Thank you @jaw!

[aymanbagabas]

Seems like there's a race condition with this change:

==================
WARNING: DATA RACE
Read at 0x00c00038c290 by main goroutine:
  github.com/charmbracelet/soft-serve/pkg/daemon.(*GitDaemon).Close()
      /home/runner/work/soft-serve/soft-serve/pkg/daemon/daemon.go:309 +0x78
  github.com/charmbracelet/soft-serve/pkg/daemon.TestMain()
      /home/runner/work/soft-serve/soft-serve/pkg/daemon/daemon_test.go:72 +0x8e7
  main.main()
      _testmain.go:49 +0x171

Previous write at 0x00c00038c290 by goroutine 25:
  github.com/charmbracelet/soft-serve/pkg/daemon.(*GitDaemon).Start()
      /home/runner/work/soft-serve/soft-serve/pkg/daemon/daemon.go:81 +0xa6
  github.com/charmbracelet/soft-serve/pkg/daemon.TestMain.func1()
      /home/runner/work/soft-serve/soft-serve/pkg/daemon/daemon_test.go:62 +0x2e

Goroutine 25 (running) created at:
  github.com/charmbracelet/soft-serve/pkg/daemon.TestMain()
      /home/runner/work/soft-serve/soft-serve/pkg/daemon/daemon_test.go:61 +0x86a
  main.main()
      _testmain.go:49 +0x171
==================
==================
WARNING: DATA RACE
Read at 0x00c0001e2b40 by main goroutine:
  net.(*TCPListener).ok()
      /opt/hostedtoolcache/go/1.23.3/x64/src/net/tcpsock_posix.go:156 +0x33
  net.(*TCPListener).Close()
      /opt/hostedtoolcache/go/1.23.3/x64/src/net/tcpsock.go:382 +0x3d
  github.com/charmbracelet/soft-serve/pkg/daemon.(*GitDaemon).Close()
      /home/runner/work/soft-serve/soft-serve/pkg/daemon/daemon.go:309 +0x8b
  github.com/charmbracelet/soft-serve/pkg/daemon.TestMain()
      /home/runner/work/soft-serve/soft-serve/pkg/daemon/daemon_test.go:72 +0x8e7
  main.main()
      _testmain.go:49 +0x171

Previous write at 0x00c0001e2b40 by goroutine 25:
  net.(*sysListener).listenTCPProto()
      /opt/hostedtoolcache/go/1.23.3/x64/src/net/tcpsock_posix.go:193 +0x16b
  net.(*sysListener).listenTCP()
      /opt/hostedtoolcache/go/1.23.3/x64/src/net/tcpsock_posix.go:179 +0x4b7
  net.(*ListenConfig).Listen()
      /opt/hostedtoolcache/go/1.23.3/x64/src/net/dial.go:765 +0x490
  net.Listen()
      /opt/hostedtoolcache/go/1.23.3/x64/src/net/dial.go:839 +0x96
  github.com/charmbracelet/soft-serve/pkg/daemon.(*GitDaemon).Start()
      /home/runner/work/soft-serve/soft-serve/pkg/daemon/daemon.go:77 +0x74
  github.com/charmbracelet/soft-serve/pkg/daemon.TestMain.func1()
      /home/runner/work/soft-serve/soft-serve/pkg/daemon/daemon_test.go:62 +0x2e

Goroutine 25 (running) created at:
  github.com/charmbracelet/soft-serve/pkg/daemon.TestMain()
      /home/runner/work/soft-serve/soft-serve/pkg/daemon/daemon_test.go:61 +0x86a
  main.main()
      _testmain.go:49 +0x171
==================
Found 2 data race(s)
FAIL	github.com/charmbracelet/soft-serve/pkg/daemon	1.068s
ok  	github.com/charmbracelet/soft-serve/pkg/db	1.012s [no tests to run]
ok  	github.com/charmbracelet/soft-serve/pkg/db/migrate	1.012s [no tests to run]
FAIL