refactor(logging): add a logging abstraction and move the job logger onto it (#1295)

Add `act/common/logging`: a printf-style `Logger` on a slog-shaped `Handler`, with a logrus-backed handler as the only backend, plus a `logtest` handler for tests. Move the job logger onto it: `common.Logger` returns `*logging.Logger`, the job log formatters and the `Reporter` hook become handlers, and composite step IDs travel in the context.

Logging is tightly coupled to logrus types (hooks, formatters, `Entry.Data`). Going through our own interface first lets the remaining call sites move over with unchanged behavior, and lets the backend be swapped for `log/slog` in one place afterwards. The global process logger and its masking formatter stay on logrus for now.

Assisted-by: Codet
Co-authored-by: bircni <[email protected]>
Reviewed-on: https://gitea.com/gitea/runner/pulls/1295
Reviewed-by: bircni <[email protected]>

act/common/logging/global.go

@@ -0,0 +1,32 @@
+// Copyright 2026 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package logging
+
+import "github.com/sirupsen/logrus"
+
+var std = New(NewLogrusHandler(logrus.StandardLogger()))
+
+// Default returns the process-wide Logger.
+func Default() *Logger { return std }
+
+// SetLevel sets the minimum level of the process-wide Logger.
+func SetLevel(level Level) { logrus.SetLevel(toLogrusLevel(level)) }
+
+// GetLevel returns the minimum level of the process-wide Logger.
+func GetLevel() Level { return fromLogrusLevel(logrus.GetLevel()) }
+
+func Enabled(level Level) bool { return std.Enabled(level) }
+
+func With(args ...any) *Logger          { return std.With(args...) }
+func WithError(err error) *Logger       { return std.WithError(err) }
+func Tracef(format string, args ...any) { std.logf(LevelTrace, format, args) }
+func Debugf(format string, args ...any) { std.logf(LevelDebug, format, args) }
+func Infof(format string, args ...any)  { std.logf(LevelInfo, format, args) }
+func Warnf(format string, args ...any)  { std.logf(LevelWarn, format, args) }
+func Errorf(format string, args ...any) { std.logf(LevelError, format, args) }
+func Trace(args ...any)                 { std.log(LevelTrace, args) }
+func Debug(args ...any)                 { std.log(LevelDebug, args) }
+func Info(args ...any)                  { std.log(LevelInfo, args) }
+func Warn(args ...any)                  { std.log(LevelWarn, args) }
+func Error(args ...any)                 { std.log(LevelError, args) }