refactor: drop logrus and other direct dependencies (#1319)

After https://gitea.com/gitea/runner/pulls/1304, logrus stayed only to forward logs from docker/cli and moby/go-archive. The runner used a small part of those: volume parsing, the build context tar, the `ssh://` connection and registry credentials. Own code that matches them replaces them, so logrus leaves the module graph. docker/cli stays for its logrus-free `opts` and `connhelper/ssh` packages.

Other dependencies that the standard library or existing ones cover go too: mergo, httprouter (replaced by `http.ServeMux`), retry-go, go-isatty, go-selinux, container-device-interface, gotest.tools and go-cmp (replaced by testify). The binary shrinks by 5%.

Behaviour differences:

1. An unreadable file in a build context is skipped with a warning, where go-archive left a truncated tar.
2. Build contexts no longer carry `security.capability` xattrs.
3. The cache and artifact servers answer HEAD on GET routes, and no longer redirect trailing slashes or answer OPTIONS.

*Written by Claude.*

---------

Co-authored-by: bircni <[email protected]>
Reviewed-on: https://gitea.com/gitea/runner/pulls/1319
Reviewed-by: bircni <[email protected]>
Reviewed-by: Lunny Xiao <[email protected]>
Co-authored-by: silverwind <[email protected]>

act/common/logging/logging_test.go

@@ -13,7 +13,6 @@ import (
 	"gitea.com/gitea/runner/act/common/logging"
 	"gitea.com/gitea/runner/act/common/logging/logtest"
 
-	"github.com/sirupsen/logrus"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
@@ -132,43 +131,6 @@ func TestSlogHandler(t *testing.T) {
 	assert.Contains(t, out, "error=boom")
 }
 
-func TestLogrusBridge(t *testing.T) {
-	prevLevel, prevDefault := logging.GetLevel(), logging.Default()
-	t.Cleanup(func() {
-		logging.SetLevel(prevLevel)
-		logging.SetReportCaller(false)
-		logging.SetDefault(prevDefault)
-	})
-	logging.SetLevel(logging.LevelInfo)
-	assert.False(t, logrus.IsLevelEnabled(logrus.DebugLevel))
-	logging.SetLevel(logging.LevelTrace)
-	logging.SetReportCaller(true)
-	h := logtest.NewWithLevel(logging.LevelTrace)
-	logging.SetDefault(logging.New(h))
-
-	logrus.WithField("lib", "docker").Warnf("from a library %d", 1)
-	_, _, line, _ := runtime.Caller(0)
-	logrus.Debug("below")
-	logrus.Trace("lowest")
-
-	recs := h.AllRecords()
-	require.Len(t, recs, 3)
-	assert.Equal(t, "from a library 1", recs[0].Message)
-	assert.Equal(t, logging.LevelWarn, recs[0].Level)
-	v, _ := recs[0].Attr("lib")
-	assert.Equal(t, "docker", v)
-	assert.Equal(t, logging.LevelDebug, recs[1].Level)
-	f := frameOf(t, recs[1].PC)
-	assert.True(t, strings.HasSuffix(f.Function, "TestLogrusBridge"), f.Function)
-	assert.Equal(t, line+1, f.Line)
-	assert.Equal(t, logging.LevelTrace, recs[2].Level)
-
-	h = logtest.New() // logrus passes Debug, the Logger does not
-	logging.SetDefault(logging.New(h))
-	logrus.Debug("dropped")
-	assert.Empty(t, h.AllRecords())
-}
-
 func TestSlogBridge(t *testing.T) {
 	h := logtest.SetDefault(t)
 	slog.With("lib", "actionslib").Warn("from a library", "n", 1)
@@ -185,19 +147,3 @@ func TestSlogBridge(t *testing.T) {
 	assert.EqualValues(t, 1, n)
 	assert.Equal(t, line-1, frameOf(t, recs[0].PC).Line)
 }
-
-func TestLogrusBridgeIntact(t *testing.T) {
-	assert.True(t, logging.LogrusBridgeIntact())
-
-	prev := logrus.StandardLogger().Out
-	t.Cleanup(func() { logrus.SetOutput(prev) })
-	logrus.SetOutput(&strings.Builder{}) // what a dependency doing this would do
-	assert.False(t, logging.LogrusBridgeIntact())
-	logrus.SetOutput(prev)
-	assert.True(t, logging.LogrusBridgeIntact())
-
-	prevLevel := logrus.GetLevel()
-	t.Cleanup(func() { logrus.SetLevel(prevLevel) })
-	logrus.SetLevel(logrus.PanicLevel)
-	assert.False(t, logging.LogrusBridgeIntact())
-}