chore(actions): support cron schedule task (#26655)

Replace #22751 

1. only support the default branch in the repository setting.
2. autoload schedule data from the schedule table after starting the
service.
3. support specific syntax like `@yearly`, `@monthly`, `@weekly`,
`@daily`, `@hourly`

## How to use

See the [GitHub Actions
document](https://docs.github.com/en/actions/using-workflows/events-that-trigger-workflows#schedule)
for getting more detailed information.

```yaml
on:
  schedule:
    - cron: '30 5 * * 1,3'
    - cron: '30 5 * * 2,4'

jobs:
  test_schedule:
    runs-on: ubuntu-latest
    steps:
      - name: Not on Monday or Wednesday
        if: github.event.schedule != '30 5 * * 1,3'
        run: echo "This step will be skipped on Monday and Wednesday"
      - name: Every time
        run: echo "This step will always run"
```

Signed-off-by: Bo-Yi.Wu <appleboy.tw@gmail.com>

---------


Co-authored-by: Jason Song <i@wolfogre.com>
Co-authored-by: techknowlogick <techknowlogick@gitea.io>
Co-authored-by: wxiaoguang <wxiaoguang@gmail.com>
Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

models/migrations/v1_21/v273.go

@@ -0,0 +1,45 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package v1_21 //nolint
+import (
+	"code.gitea.io/gitea/modules/timeutil"
+
+	"xorm.io/xorm"
+)
+
+func AddActionScheduleTable(x *xorm.Engine) error {
+	type ActionSchedule struct {
+		ID            int64
+		Title         string
+		Specs         []string
+		RepoID        int64 `xorm:"index"`
+		OwnerID       int64 `xorm:"index"`
+		WorkflowID    string
+		TriggerUserID int64
+		Ref           string
+		CommitSHA     string
+		Event         string
+		EventPayload  string `xorm:"LONGTEXT"`
+		Content       []byte
+		Created       timeutil.TimeStamp `xorm:"created"`
+		Updated       timeutil.TimeStamp `xorm:"updated"`
+	}
+
+	type ActionScheduleSpec struct {
+		ID         int64
+		RepoID     int64 `xorm:"index"`
+		ScheduleID int64 `xorm:"index"`
+		Spec       string
+		Next       timeutil.TimeStamp `xorm:"index"`
+		Prev       timeutil.TimeStamp
+
+		Created timeutil.TimeStamp `xorm:"created"`
+		Updated timeutil.TimeStamp `xorm:"updated"`
+	}
+
+	return x.Sync(
+		new(ActionSchedule),
+		new(ActionScheduleSpec),
+	)
+}